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The physicochemical properties of synthetically produced bone substitute materials (BSM) have a major impact on biocompatibility. This affects bony tissue integration, osteoconduction, as well as the degradation pattern and the correlated inflammatory tissue responses including macrophages and multinucleated giant cells (MNGCs). Thus, influencing factors such as size, special surface morphologies, porosity, and interconnectivity have been the subject of extensive research. In the present publication, the influence of the granule size of three identically manufactured bone substitute granules based on the technology of hydroxyapatite (HA)-forming calcium phosphate cements were investigated, which includes the inflammatory response in the surrounding tissue and especially the induction of MNGCs (as a parameter of the material degradation). For the in vivo study, granules of three different size ranges (small = 0.355–0.5 mm; medium = 0.5–1 mm; big = 1–2 mm) were implanted in the subcutaneous connective tissue of 45 male BALB/c mice. At 10, 30, and 60 days post implantationem, the materials were explanted and histologically processed. The defect areas were initially examined histopathologically. Furthermore, pro- and anti-inflammatory macrophages were quantified histomorphometrically after their immunohistochemical detection. The number of MNGCs was quantified as well using a histomorphometrical approach. The results showed a granule size-dependent integration behavior. The surrounding granulation tissue has passivated in the groups of the two bigger granules at 60 days post implantationem including a fibrotic encapsulation, while a granulation tissue was still present in the group of the small granules indicating an ongoing cell-based degradation process. The histomorphometrical analysis showed that the number of proinflammatory macrophages was significantly increased in the small granules at 60 days post implantationem. Similarly, a significant increase of MNGCs was detected in this group at 30 and 60 days post implantationem. Based on these data, it can be concluded that the integration and/or degradation behavior of synthetic bone substitutes can be influenced by granule size.
Different types of raw cotton were investigated by a commercial ultraviolet-visible/near infrared (UV-Vis/NIR) spectrometer (210–2200 nm) as well as on a home-built setup for NIR hyperspectral imaging (NIR-HSI) in the range 1100–2200 nm. UV-Vis/NIR reflection spectroscopy reveals the dominant role proteins, hydrocarbons and hydroxyl groups play in the structure of cotton. NIR-HSI shows a similar result. Experimentally obtained data in combination with principal component analysis (PCA) provides a general differentiation of different cotton types. For UV-Vis/NIR spectroscopy, the first two principal components (PC) represent 82 % and 78 % of the total data variance for the UV-Vis and NIR regions, respectively. Whereas, for NIR-HSI, due to the large amount of data acquired, two methodologies for data processing were applied in low and high lateral resolution. In the first method, the average of the spectra from one sample was calculated and in the second method the spectra of each pixel were used. Both methods are able to explain ≥90 % of total variance by the first two PCs. The results show that it is possible to distinguish between different cotton types based on a few selected wavelength ranges. The combination of HSI and multivariate data analysis has a strong potential in industrial applications due to its short acquisition time and low-cost development. This study opens a novel possibility for a further development of this technique towards real large-scale processes.
Hyperspectral imaging and reflectance spectroscopy in the range from 200–380 nm were used to rapidly detect and characterize copper oxidation states and their layer thicknesses on direct bonded copper in a non-destructive way. Single-point UV reflectance spectroscopy, as a well-established method, was utilized to compare the quality of the hyperspectral imaging results. For the laterally resolved measurements of the copper surfaces an UV hyperspectral imaging setup based on a pushbroom imager was used. Six different types of direct bonded copper were studied. Each type had a different oxide layer thickness and was analyzed by depth profiling using X-ray photoelectron spectroscopy. In total, 28 samples were measured to develop multivariate models to characterize and predict the oxide layer thicknesses. The principal component analysis models (PCA) enabled a general differentiation between the sample types on the first two PCs with 100.0% and 96% explained variance for UV spectroscopy and hyperspectral imaging, respectively. Partial least squares regression (PLS-R) models showed reliable performance with R2c = 0.94 and 0.94 and RMSEC = 1.64 nm and 1.76 nm, respectively. The developed in-line prototype system combined with multivariate data modeling shows high potential for further development of this technique towards real large-scale processes.
UV hyperspectral imaging (225 nm–410 nm) was used to identify and quantify the honey- dew content of real cotton samples. Honeydew contamination causes losses of millions of dollars annually. This study presents the implementation and application of UV hyperspectral imaging as a non-destructive, high-resolution, and fast imaging modality. For this novel approach, a reference sample set, which consists of sugar and protein solutions that were adapted to honeydew, was set-up. In total, 21 samples with different amounts of added sugars/proteins were measured to calculate multivariate models at each pixel of a hyperspectral image to predict and classify the amount of sugar and honeydew. The principal component analysis models (PCA) enabled a general differentiation between different concentrations of sugar and honeydew. A partial least squares regression (PLS-R) model was built based on the cotton samples soaked in different sugar and protein concentrations. The result showed a reliable performance with R2cv = 0.80 and low RMSECV = 0.01 g for the valida- tion. The PLS-R reference model was able to predict the honeydew content laterally resolved in grams on real cotton samples for each pixel with light, strong, and very strong honeydew contaminations. Therefore, inline UV hyperspectral imaging combined with chemometric models can be an effective tool in the future for the quality control of industrial processing of cotton fibers.
Due to its wide-ranging endocrine functions, adipose tissue influences the whole body’s metabolism. Engineering long-term stable and functional human adipose tissue is still challenging due to the limited availability of suitable biomaterials and adequate cell maturation. We used gellan gum (GG) to create manual and bioprinted adipose tissue models because of its similarities to the native extracellular matrix and its easily tunable properties. Gellan gum itself was neither toxic nor monocyte activating. The resulting hydrogels exhibited suitable viscoelastic properties for soft tissues and were stable for 98 days in vitro. Encapsulated human primary adipose-derived stem cells (ASCs) were adipogenically differentiated for 14 days and matured for an additional 84 days. Live-dead staining showed that encapsulated cells stayed viable until day 98, while intracellular lipid staining showed an increase over time and a differentiation rate of 76% between days 28 and 56. After 4 weeks of culture, adipocytes had a univacuolar morphology, expressed perilipin A, and secreted up to 73% more leptin. After bioprinting establishment, we demonstrated that the cells in printed hydrogels had high cell viability and exhibited an adipogenic phenotype and function. In summary, GG-based adipose tissue models show long-term stability and allow ASCs maturation into functional, univacuolar adipocytes.
Adipose tissue is related to the development and manifestation of multiple diseases, demonstrating the importance of suitable in vitro models for research purposes. In this study, adipose tissue lobuli were explanted, cultured, and used as an adipose tissue control to evaluate in vitro generated adipose tissue models. During culture, lobule exhibited a stable weight, lactate dehydrogenase, and glycerol release over 15 days. For building up in vitro adipose tissue models, we adapted the biomaterial gelatin methacryloyl (GelMA) composition and handling to homogeneously mix and bioprint human primary mature adipocytes (MA) and adipose-derived stem cells (ASCs), respectively. Accelerated cooling of the bioink turned out to be essential for the homogeneous distribution of lipid-filled MAs in the hydrogel. Last, we compared manual and bioprinted GelMA hydrogels with MA or ASCs and the explanted lobules to evaluate the impact of the printing process and rate the models concerning the physiological reference. The viability analyses demonstrated no significant difference between the groups due to additive manufacturing. The staining of intracellular lipids and perilipin A suggest that GelMA is well suited for ASCs and MA. Therefore, we successfully constructed physiological in vitro models by bioprinting MA-containing GelMA bioinks.
Influence of the respirator on volatile organic compounds : an animal study in rats over 24 hours
(2015)
Long-term animal studies are needed to accomplish measurements of volatile organic compounds (VOCs) for medical diagnostics. In order to analyze the time course of VOCs, it is necessary to ventilate these animals. Therefore, a total of 10 male Sprague–Dawley rats were anaesthetized and ventilated with synthetic air via tracheotomy for 24 h. An ion mobility spectrometry coupled to multi-capillary columns (MCC–IMS) was used to analyze the expired air. To identify background contaminations produced by the respirator itself, six comparative measurements were conducted with ventilators only. Overall, a number of 37 peaks could be detected within the positive mode. According to the ratio peak intensity rat/ peak intensity ventilator blank, 22 peaks with a ratio >1.5 were defined as expired VOCs, 12 peaks with a ratio between 0.5 and 1.5 as unaffected VOCs, and three peaks with a ratio <0.5 as resorbed VOCs. The peak intensity of 12 expired VOCs changed significantly during the 24 h measurement. These results represent the basis for future intervention studies. Notably, online VOC analysis with MCC–IMS is possible over 24 h in ventilated rats and allows different experimental approaches.
The chemical recycling of used motor oil via catalytic cracking to convert it into secondary diesel-like fuels is a sustainable and technically attractive solution for managing environmental concerns associated with traditional disposal. In this context, this study was conducted to screen basic and acidic-aluminum silicate catalysts doped with different metals, including Mg, Zn, Cu, and Ni. The catalysts were thoroughly characterized using various techniques such as N2 adsorption–desorption isotherms, FT-IR spectroscopy, and TG analysis. The liquid and gaseous products were identified using GC, and their characteristics were compared with acceptable ranges from ASTM characterization methods for diesel fuel. The results showed that metal doping improved the performance of the catalysts, resulting in higher conversion rates of up to 65%, compared to thermal (15%) and aluminum silicates (≈20%). Among all catalysts, basic aluminum silicates doped with Ni showed the best catalytic performance, with conversions and yields three times higher than aluminum silicate catalysts. These findings significantly contribute to developing efficient and eco-friendly processes for the chemical recycling of used motor oil. This study highlights the potential of basic aluminum silicates doped with Ni as a promising catalyst for catalytic cracking and encourages further research in this area.
Fast pyrolysis as a valorization mechanism for banana rachis and low-density polyethylene waste
(2021)
Banana rachis and low-density polyethylene (LDPE) were selected as secondary feedstocks for the study of fast pyrolysis in a free-fall reactor. The experiments were performed at 600 °C for banana rachis and 450 °C for LDPE, based on literature and thermogravimetric analysis. The gaseous products of both feedstocks present similar composition in the C1-C2 compounds, while C3 compounds are only found in LDPE. The liquid products from banana and LDPE correspond to functional groups and shorter hydrocarbons, respectively. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses of the char showed important morphological changes to spheres in LDPE and structural changes due to thermal decomposition in the biomass. The pyrolysis char has high potential as adsorbent, encapsulation, or catalyst.
Characterization of low density polyethylene greenhouse films during the composting of rose residues
(2022)
This study presents an evaluation of a potential alternative to plastic degradation in the form of organic composting. It stems from the urgent need of finding solutions to the plastic residues and focuses on the compost-based degradation of greenhouse film covers in an important rose exporter company in Ecuador. Thus, this study analyzes the physical, chemical, and biological changes of rose wastes composting, and also evaluates the stability of new and aged agricultural plastic under these conditions. Interestingly, results of compost characterization show a slow degradation rate of organic matter and total organic carbon, along with a significant increase in pH and rise of bacterial populations. However, the results demonstrate that despite these findings, composting conditions had no significant influence on plastic degradation, and while deterioration of aged plastic samples was reported in some tests, it may be the result of environmental conditions and a prolonged exposure to solar radiation. Importantly, these factors could facilitate the adhesion of microorganisms and promote plastic biodegradation. Hence, it is encouraged for future studies to analyze the ecotoxicity of plastics in the compost, as well as isolate, identify, and evaluate the possible biodegradative potential of these microorganisms as an alternative to plastic waste management.
The effect of Hofmeister anions on the surface properties of polyelectrolyte multilayers built from hyaluronan and chitosan by layer-by-layer deposition is studied by ellipsometry and atomic force microscopy. The thickness, roughness and morphology of the resulting coatings were found to depend on the type of the anion. Relationship between the surface properties and the biological response of the polyelectrolyte multilayers is established by assessing the degree of protein (albumin) adsorption.
The properties of polyelectrolyte multilayers are ruled by the process parameters employed during self-assembly. This is the first study in which a design of experiment approach was used to validate and control the production of ultrathin polyelectrolyte multilayer coatings by identifying the ranges of critical process parameters (polyelectrolyte concentration, ionic strength and pH) within which coatings with reproducible properties (thickness, refractive index and hydrophilicity) are created. Mathematical models describing the combined impact of key process parameters on coatings properties were developed demonstrating that only ionic strength and pH affect the coatings thickness, but not polyelectrolyte concentration. While the electrolyte concentration had a linear effect, the pH contribution was described by a quadratic polynomial. A significant contribution of this study is the development of a new approach to estimate the thickness of polyelectrolyte multilayer nanofilms by quantitative rhodamine B staining, which might be useful in all cases when ellipsometry is not feasible due to the shape complexity or small size of the coated substrate. The novel approach proposed here overcomes the limitations of known methods as it offers a low spatial sampling size and the ability to analyse a wide area without restrictions on the chemical composition and shape of the substrate.
Controlling the surface properties and structure of thin nanosized coatings is of primary importance in diverse engineering and medical applications. Here we report on how the nanostructure, growth mechanism, thickness, roughness, and hydrophilicity of nanocomposites composed of weak natural or strong synthetic polyelectrolytes (PE) can be tailored by graphene oxide (GO) doping. GO reverses the build‐up mechanism affecting the internal structure and the hydrophilicity in a way depending on the type of the PE‐matrix. The extent of GO‐adsorption and its impact on the surface morphology was found to be independent on the type of the underlying PE‐matrix. The nanostructure of the hybrid films is not significantly altered when a single surface‐exposed GO‐layer is deposited, while increasing the number of embedded GO‐layers leads to pronounced surface heterogeneity. These results are expected to have valuable impact on the construction strategies of coatings with tunable surface properties.
Herein the optimization of the physicochemical properties and surface biocompatibility of polyelectrolyte multilayers of the natural, biocompatible and biodegradable, linear polysaccharides hyaluronan and chitosan by Hofmeister anions was systematically investigated. We demonstrated that there is an interconnection between the bulk and surface properties of HA/Chi multilayers both varying in accordance with the arrangement of the anions in the Hofmeister series. Kosmotropic anions increased the hydration, thickness, micro- and macro-roughness, and hydrophilicity and improved the biocompatibility of the films by reduction (2 orders of magnitude) of the films stiffness and complete anti-thrombogenicity.
This paper is concerned with the study, optimization and control of the moisture sorption kinetics of agricultural products at temperatures typically found in processing and storage. A nonlinear autoregressive with exogenous inputs (NARX) neural network was developed to predict moisture sorption kinetics and consequently equilibrium moisture contents of shiitake mushrooms (Lentinula edodes (Berk.) Pegler) over a wide range of relative humidity and different temperatures. Sorption kinetic data of mushroom caps was separately generated using a continuous, gravimetric dynamic vapour sorption analyser at emperatures of 25-40 °C over a stepwise variation of relative humidity ranging from 0 to 85%. The predictive power of the neural network was based on physical data, namely relative humidity and temperature. The model was fed with a total of 4500 data points by dividing them into three subsets, namely, 70% of the data was used for training, 15% of the data for testing and 15% of the data for validation, randomly selected from the whole dataset. The NARX neural network was capable of precisely simulating equilibrium moisture contents of mushrooms derived from the dynamic vapour sorption kinetic data throughout the entire range of relative humidity.
We report the temperature dependence of metal-enhanced fluorescence (MEF) of individual photosystem I (PSI) complexes from Thermosynechococcus elongatus (T. elongatus) coupled to gold nanoparticles (AuNPs). A strong temperature dependence of shape and intensity of the emission spectra is observed when PSI is coupled to AuNPs. For each temperature, the enhancement factor (EF) is calculated by comparing the intensity of individual AuNP-coupled PSI to the mean intensity of ‘uncoupled’ PSI. At cryogenic temperature (1.6 K) the average EF was 4.3-fold. Upon increasing the temperature to 250 K the EF increases to 84-fold. Single complexes show even higher EFs up to 441.0-fold. At increasing temperatures the different spectral pools of PSI from T. elongatus become distinguishable. These pools are affected differently by the plasmonic interactions and show different enhancements. The remarkable increase of the EFs is explained by a rate model including the temperature dependence of the fluorescence yield of PSI and the spectral overlap between absorption and emission spectra of AuNPs and PSI, respectively.
Thermoplastic polycarbonate urethane elastomers (TPCU) are potential implant materials for treating degenerative joint diseases thanks to their adjustable rubber-like properties, their toughness, and their durability. We developed a water-containing high-molecular-weight sulfated hyaluronic acid-coating to improve the interaction of TPCU with the synovial fluid. It is suggested that trapped synovial fluid can act as a lubricant that reduces the friction forces and thus provides an enhanced abrasion resistance of TPCU implants. Aims of this work were (i) the development of a coating method for novel soft TPCU with high-molecular sulfated hyaluronic acid to increase the biocompatibility and (ii) the in vitro validation of the functionalized TPCUs in cell culture experiments.
Knee osteoarthritis is a common complication and can lead to total loss of joint function in patients. Treatment by either partial or total knee replacement with appropriate UHMWPE based implantsis highly invasive, may cause complications and may show unsatisfying results. Alternatively, treatment may be done by insertion of an elastic interpositional knee spacer with optimized material characteristics.
We report the development of high performance polyurethane-based polymers modified with bioactive molecules for fabrication of such knee spacers. In order to tailor mechanical and tribological properties and to improve resist to enzymatic degradation we propose a core-shell model for the spacer with specifically adapted properties.
Polyurethane-bases block copolymers (TPCUs) are block-copolymers with systematically varied soft and hard segments. They have been suggested to serve as material for chondral implants in joint regeneration. Such applications may require the adhesion of chondrocytes to the implant surface, facilitating cell growth while keeping their phenotype. Thus, aims of this work were (1) to modify the surface of soft biostable polyurethane-based model implants (TPCU and TSiPCU) with high-molecular weight hyaluronic acid (HA) using an optimized multistep strategy of immobilization, and (2) to evaluate bioactivity of the modified TPCUs in vitro. Our results show no cytotoxic potential of the TPCUs. HAbioactive molecules (Mw =700kDa) were immobilized onto the polyurethane surface via polyethylenimine (PEI) spacers, and modifications were confirmed by several characterization methods. Tests with porcine chondrocytes indicated the potential of the TPCU-HA for inducing enhanced cell proliferation.
Background
Alzheimer’s disease (AD) is diagnosed based upon medical history, neuropsychiatric examination, cerebrospinal fluid analysis, extensive laboratory analyses and cerebral imaging. Diagnosis is time consuming and labour intensive. Parkinson’s disease (PD) is mainly diagnosed on clinical grounds.
Objective
The primary aim of this study was to differentiate patients suffering from AD, PD and healthy controls by investigating exhaled air with the electronic nose technique. After demonstrating a difference between the three groups the secondary aim was the identification of specific substances responsible for the difference(s) using ion mobility spectroscopy. Thirdly we analysed whether amyloid beta (Aβ) in exhaled breath was causative for the observed differences between patients suffering from AD and healthy controls.
Methods
We employed novel pulmonary diagnostic tools (electronic nose device/ion-mobility spectrometry) for the identification of patients with neurodegenerative diseases. Specifically, we analysed breath pattern differences in exhaled air of patients with AD, those with PD and healthy controls using the electronic nose device (eNose). Using ion mobility spectrometry (IMS), we identified the compounds responsible for the observed differences in breath patterns. We applied ELISA technique to measure Aβ in exhaled breath condensates.
Results
The eNose was able to differentiate between AD, PD and HC correctly. Using IMS, we identified markers that could be used to differentiate healthy controls from patients with AD and PD with an accuracy of 94%. In addition, patients suffering from PD were identified with sensitivity and specificity of 100%. Altogether, 3 AD patients out of 53 participants were misclassified. Although we found Aβ in exhaled breath condensate from both AD and healthy controls, no significant differences between groups were detected.
Conclusion
These data may open a new field in the diagnosis of neurodegenerative disease such as Alzheimer’s disease and Parkinson’s disease. Further research is required to evaluate the significance of these pulmonary findings with respect to the pathophysiology of neurodegenerative disorders.
The powder coating of veneered particle boards by the sequence electrostatic powder application -powder curing via hot pressing is studied in order to create high gloss surfaces. To obtain an appealingaspect, veneer Sheets were glued by heat and pressure on top of particle boards and the resulting surfaceswere used as carrier substrates for powder coat finishing. Prior to the powder coating, the veneeredparticle board surfaces were pre-treated by sanding to obtain good uniformity and the boards werestored in a climate chamber at controlled temperature and humidity conditions to adjust an appropriate electrical surface resistance. Characterization of surface texture was done by 3D microscopy. The surfaceelectrical resistance was measured for the six veneers before and after their application on the particleboard surface. A transparent powder top-coat was applied electrostatically onto the veneered particleboard surface. Curing of the powder was done using a heated press at 130◦C for 8 min and a smooth, glossy coating was obtained on the veneered surfaces. By applying different amounts of powder thecoating thickness could be varied and the optimum amount of powder was determined for each veneer type.
In the powder coating of veneered particle boards the highly reactive hybrid epoxy/polyester powder transparent Drylac 530 Series from TIGER Coatings GmbH & Co. KG, Wels, Austria was used. Curing is accelerated by a mixture of catalysts reaching curing times of 3 min at 150 °C or 5 min at 135 °C which allows for energy and time savings making Drylac Series 530 powder suitable for the coating of temperaturesensitive substrates such as MDF and wood.
Decorative laminates based on melamine formaldehyde (MF) resin impregnated papers are used at great extent for surface finishing of engineered wood that is used for furniture, kitchen, and working surfaces, flooring and exterior cladding. In all these applications, optically flawless appearance is a major issue. The work described here is focused on enhancing the cleanability and antifingerprint properties of smooth, matt surface-finished melamine-coated particleboards for furniture fronts, without at the same time changing or deteriorating other important surface parameters such as hardness, roughness or gloss. In order to adjust the surface polarity of a low pressure melamine film, novel interface-active macromolecular compounds were prepared and tested for their suitability as an antifingerprint additive. Two hydroxy-functional surfactants (polydimethysiloxane, PDMS-OH and perfluoroether, PF-OH) were oxidized under mild conditions to the corresponding aldehydes (PDMS-CHO and PF-CHO) using a pyridinium chlorochromate catalyst. With the most promising oxidized polymeric additive, PDMS-CHO, the contact angles against water, n-hexadecane, and squalene increased from 79.8°, 26.3° and 31.4° for the pure MF surface to 108.5°, 54.8°, and 59.3°, respectively, for the modified MF surfaces. While for the laminated MF surface based on the oxidized fluoroether the gloss values were much higher than required, for the surfaces based on oxidized polydimethylsiloxane the technological values as well as the lower gloss values were in agreement with the requirements and showed much improved surface cleanability, as was also confirmed by colorimetric measurements.
Unprecedented formation of sterically stabilized phospholipid liposomes of cuboidal morphology
(2021)
Sterically stabilized phospholipid liposomes of unprecedented cuboid morphology are formed upon introduction in the bilayer membrane of original polymers, based on polyglycidol bearing a lipid-mimetic residue. Strong hydrogen bonding in the polyglycidol sublayers creates attractive forces, which, facilitated by fluidization of the membrane, bring about the flattening of the bilayers and the formation of cuboid vesicles.
The present publication reports the purification effort of two natural bone blocks, that is, an allogeneic bone block (maxgraft®, botiss biomaterials GmbH, Zossen, Germany) and a xenogeneic block (SMARTBONE®, IBI S.A., Mezzovico Vira, Switzerland) in addition to previously published results based on histology. Furthermore, specialized scanning electron microscopy (SEM) and in vitro analyses (XTT, BrdU, LDH) for testing of the cytocompatibility based on ISO 10993-5/-12 have been conducted. The microscopic analyses showed that both bone blocks possess a trabecular structure with a lamellar subarrangement. In the case of the xenogeneic bone block, only minor remnants of collagenous structures were found, while in contrast high amounts of collagen were found associated with the allogeneic bone matrix. Furthermore, only island-like remnants of the polymer coating in case of the xenogeneic bone substitute seemed to be detectable. Finally, no remaining cells or cellular remnants were found in both bone blocks. The in vitro analyses showed that both bone blocks are biocompatible. Altogether, the purification level of both bone blocks seems to be favorable for bone tissue regeneration without the risk for inflammatory responses or graft rejection. Moreover, the analysis of the maxgraft® bone block showed that the underlying purification process allows for preserving not only the calcified bone matrix but also high amounts of the intertrabecular collagen matrix.
Introduction: Bioresorbable collagenous barrier membranes are used to prevent premature soft tissue ingrowth and to allow bone regeneration. For volume stable indications, only non-absorbable synthetic materials are available. This study investigates a new bioresorbable hydrofluoric acid (HF)-treated magnesium (Mg) mesh in a native collagen membrane for volume stable situations. Materials and Methods: HF-treated and untreated Mg were compared in direct and indirect cytocompatibility assays. In vivo, 18 New Zealand White Rabbits received each four 8 mm calvarial defects and were divided into four groups: (a) HF-treated Mg mesh/collagen membrane, (b) untreated Mg mesh/collagen membrane (c) collagen membrane and (d) sham operation. After 6, 12 and 18 weeks, Mg degradation and bone regeneration was measured using radiological and histological methods. Results: In vitro, HF-treated Mg showed higher cytocompatibility. Histopathologically, HF-Mg prevented gas cavities and was degraded by mononuclear cells via phagocytosis up to 12 weeks. Untreated Mg showed partially significant more gas cavities and a fibrous tissue reaction. Bone regeneration was not significantly different between all groups. Discussion and Conclusions: HF-Mg meshes embedded in native collagen membranes represent a volume stable and biocompatible alternative to the non-absorbable synthetic materials. HF-Mg shows less corrosion and is degraded by phagocytosis. However, the application of membranes did not result in higher bone regeneration.
Different sensor types using chemical and biochemical principles are described. The former are mainly gas sensors, the latter are applied especially to liquids. Those label-free direct detection methods are compared with applications where assays take advantage of labeled receptors.
Furthermore, selected applications in the area of gas sensors are discussed, and sensors for process control, point-of-care diagnostics, environmental analytics, and food analytics are reviewed. In addition, multiplexing approaches used in microplates and microarrays are described.
On account of the huge number of sensor types and the wide range of possible applications, only the most important ones are selected here.
Salivary gland tumors (SGTs) are a relevant, highly diverse subgroup of head and neck tumors whose entity determination can be difficult. Confocal Raman imaging in combination with multivariate data analysis may possibly support their correct classification. For the analysis of the translational potential of Raman imaging in SGT determination, a multi-stage evaluation process is necessary. By measuring a sample set of Warthin tumor, pleomorphic adenoma and non-tumor salivary gland tissue, Raman data were obtained and a thorough Raman band analysis was performed. This evaluation revealed highly overlapping Raman patterns with only minor spectral differences. Consequently, a principal component analysis (PCA) was calculated and further combined with a discriminant analysis (DA) to enable the best possible distinction. The PCA-DA model was characterized by accuracy, sensitivity, selectivity and precision values above 90% and validated by predicting model-unknown Raman spectra, of which 93% were classified correctly. Thus, we state our PCA-DA to be suitable for parotid tumor and non-salivary salivary gland tissue discrimination and prediction. For evaluation of the translational potential, further validation steps are necessary.
Glioblastoma WHO IV belongs to a group of brain tumors that are still incurable. A promising treatment approach applies photodynamic therapy (PDT) with hypericin as a photosensitizer. To generate a comprehensive understanding of the photosensitizer-tumor interactions, the first part of our study is focused on investigating the distribution and penetration behavior of hypericin in glioma cell spheroids by fluorescence microscopy. In the second part, fluorescence lifetime imaging microscopy (FLIM) was used to correlate fluorescence lifetime (FLT) changes of hypericin to environmental effects inside the spheroids. In this context, 3D tumor spheroids are an excellent model system since they consider 3D cell–cell interactions and the extracellular matrix is similar to tumors in vivo. Our analytical approach considers hypericin as probe molecule for FLIM and as photosensitizer for PDT at the same time, making it possible to directly draw conclusions of the state and location of the drug in a biological system. The knowledge of both state and location of hypericin makes a fundamental understanding of the impact of hypericin PDT in brain tumors possible. Following different incubation conditions, the hypericin distribution in peripheral and central cryosections of the spheroids were analyzed. Both fluorescence microscopy and FLIM revealed a hypericin gradient towards the spheroid core for short incubation periods or small concentrations. On the other hand, a homogeneous hypericin distribution is observed for long incubation times and high concentrations. Especially, the observed FLT change is crucial for the PDT efficiency, since the triplet yield, and hence the O2 activation, is directly proportional to the FLT. Based on the FLT increase inside spheroids, an incubation time 30 min is required to achieve most suitable conditions for an effective PDT.
The early detection of head and neck cancer is a prolonged challenging task. It requires a precise and accurate identification of tissue alterations as well as a distinct discrimination of cancerous from healthy tissue areas. A novel approach for this purpose uses microspectroscopic techniques with special focus on hyperspectral imaging (HSI) methods. Our proof-of-principle study presents the implementation and application of darkfield elastic light scattering spectroscopy (DF ELSS) as a non-destructive, high-resolution, and fast imaging modality to distinguish lingual healthy from altered tissue regions in a mouse model. The main aspect of our study deals with the comparison of two varying HSI detection principles, which are a point-by-point and line scanning imaging, and whether one might be more appropriate in differentiating several tissue types. Statistical models are formed by deploying a principal component analysis (PCA) with the Bayesian discriminant analysis (DA) on the elastic light scattering (ELS) spectra. Overall accuracy, sensitivity, and precision values of 98% are achieved for both models whereas the overall specificity results in 99%. An additional classification of model-unknown ELS spectra is performed. The predictions are verified with histopathological evaluations of identical HE-stained tissue areas to prove the model’s capability of tissue distinction. In the context of our proof-of-principle study, we assess the Pushbroom PCA-DA model to be more suitable for tissue type differentiations and thus tissue classification. In addition to the HE-examination in head and neck cancer diagnosis, the usage of HSI-based statistical models might be conceivable in a daily clinical routine.
Die Ionenmobilitätsspektrometrie ist eine gasanalytische Methode, die analytisch zwischen Sensoren auf der einen Seite und Spektrometern auf der anderen angesiedelt ist. Ihre Vorteile liegen darin, auch komplexere Gasgemische als Sensoren erfolgreich vor Ort und online sowie bettseitig im Krankenhaus analysieren zu können. Beispiele als dem Bereich Bio- und Prozessanalytik sollen die jeweiligen Ansätze und das Potential von der Fragestellung über die jeweils spezifische Lösung bis hin zum Ergebnis am Prozess exemplarisch zusammenstellen. Hierbei werden sowohl die analytische Sicht als auch die Marktsicht thematisiert.
The number of publications in the field of breath analysis using different types of ion mobility spectrometers (IMS) has increased over the last few years. In this paper, the publications between 2010 and 2013 are reviewed with respect to different types of IMS such as differential mobility spectrometers, high-field asymmetric waveform ion mobility spectrometers and multi-capillary columns coupled to conventional IMS. The analytes detected by IMS and declared with significance to a specific medical question were considered further with respect to medical and analytical questions. In total, 42 different analytes were found to be detected using IMS on a high significance level and were compared to findings using other analytical methods with respect to the individual analyte.
Background: Conventional methods for lung cancer detection including computed tomography (CT) and bronchoscopy are expensive and invasive. Thus, there is still a need for an optimal lung cancer detection technique. Methods: The exhaled breath of 50 patients with lung cancer histologically proven by bronchoscopic biopsy samples (32 adenocarcinomas, 10 squamous cell carcinomas, 8 small cell carcinomas), were analyzed using ion mobility spectrometry (IMS) and compared with 39 healthy volunteers. As a secondary assessment, we compared adenocarcinoma patients with and without epidermal growth factor receptor (EGFR) mutation. Results: A decision tree algorithm could separate patients with lung cancer including adenocarcinoma, squamous cell carcinoma and small cell carcinoma. One hundred-fifteen separated volatile organic compound (VOC) peaks were analyzed. Peak-2 noted as n-Dodecane using the IMS database was able to separate values with a sensitivity of 70.0% and a specificity of 89.7%. Incorporating a decision tree algorithm starting with n-Dodecane, a sensitivity of 76% and specificity of 100% was achieved. Comparing VOC peaks between adenocarcinoma and healthy subjects, n-Dodecane was able to separate values with a sensitivity of 81.3% and a specificity of 89.7%. Fourteen patients positive for EGFR mutation displayed a significantly higher n-Dodecane than for the 14 patients negative for EGFR (p<0.01), with a sensitivity of 85.7% and a specificity of 78.6%. Conclusion: In this prospective study, VOC peak patterns using a decision tree algorithm were useful in the detection of lung cancer. Moreover, n-Dodecane analysis from adenocarcinoma patients might be useful to discriminate the EGFR mutation.
Pre-clinical evaluation of advanced nerve guide conduits using a novel 3D in vitro testing model
(2018)
Autografts are the current gold standard for large peripheral nerve defects in clinics despite the frequently occurring side effects like donor site morbidity. Hollow nerve guidance conduits (NGC) are proposed alternatives to autografts, but failed to bridge gaps exceeding 3 cm in humans. Internal NGC guidance cues like microfibres are believed to enhance hollow NGCs by giving additional physical support for directed regeneration of Schwann cells and axons. In this study, we report a new 3D in vitro model that allows the evaluation of different intraluminal fibre scaffolds inside a complete NGC. The performance of electrospun polycaprolactone (PCL) microfibres inside 5 mm long polyethylene glycol (PEG) conduits were investigated in neuronal cell and dorsal root ganglion (DRG) cultures in vitro. Z-stack confocal microscopy revealed the aligned orientation of neuronal cells along the fibres throughout the whole NGC length and depth. The number of living cells in the centre of the scaffold was not significantly different to the tissue culture plastic (TCP) control. For ex vivo analysis, DRGs were placed on top of fibre-filled NGCs to simulate the proximal nerve stump. In 21 days of culture, Schwann cells and axons infiltrated the conduits along the microfibres with 2.2 ± 0.37 mm and 2.1 ± 0.33 mm, respectively. We conclude that this in vitro model can help define internal NGC scaffolds in the future by comparing different fibre materials, composites and dimensions in one setup prior to animal testing.
In thermopervaporation the same economically favorable driving force as in membrane distillation, i.e., a temperature difference between feed and permeate for the transport, is used but with non-porous thin-film composite membranes. Membrane pores cannot be wetted and long-term operational stability can be achieved with the appropriate coating layer, but normally with a decrease of the flux compared to membrane distillation with porous hydrophobic membranes.
Porous asymmetric PVDF membranes were made to achieve low permeation resistance and pores which could be overcoated with polyelectrolyte polymers. This coating prohibits pore wetting and strongly reduces adsorption of organic substances.
Those membranes showed a high permeation rate for water due to a structure of phase-separated hydrophilic and hydrophobic three-dimensional domains. The permeation rates of these composite membranes for water is between 6 and 12 l/(h m²) at a feed temperature of 60 °C and permeate at a temperature of 40 °C of a 2% saline solution feed depending on the operational parameters. This is only a slight reduction of 10–15% in permeation rate compared to membrane distillation with porous hydrophobic membranes.
In whey dewatering experiment this membrane showed a constant performance over 4 days in intermittent operation mode and stability in cleaning with strong alkaline solution.
A vapor permeation processes for the separation of aromatic compounds from aliphatic compounds
(2014)
A number of rubbery and glassy membranes have been prepared and evaluated in vapor permeation experiments for separation of aromatic/aliphatic mixtures, using 5/95 (wt:wt) toluene/methylcyclohexane (MCH) as a model solution. Candidate membranes that met the required toluene/MCH selectivity of ≥ 10 were identified. The stability of the candidate membranes was tested by cycling the experiment between higher toluene concentrations and the original 5 wt% level. The best membrane produced has a toluene permeance of 280 gpu and a toluene/MCH selectivity of 13 when tested with a vapor feed of the model mixture at its boiling point and at atmospheric pressure. When a series of related membrane materials are compared, there is a sharp trade-off between membrane permeance and membrane selectivity. A process design study based on the experimental results was conducted. The best preliminary membrane design uses 45% of the energy of a conventional distillation process.
Long-term stability of membranes in membrane distillation operation is a problem nowadays which prevents the industrial breakthrough of this separation process. Fouling or slow pore wetting are the basic reasons for this.
Membrane distillation membranes were made by NIPS process rendering the membrane asymmetrically to achieve low permeation resistance and pores which can be over coated with polyelectrolyte polymers thus leading to thermopervaporation membranes. Those membranes prohibit pore wetting and may strongly reduce resorption of organic substances on for membrane distillation typically used hydrophobic surfaces thus leading to longterm operation stability in dewatering including stable membrane cleaning.
Asymmetric PVDF membranes have been coated with cation exchange polyelectrolyte leading to a very thin, defect-free layer which has a high permeation rate for water due to the domain structure of phase-separated hydrophilic and hydrophobic three-dimensional structures.
Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease characterized by incompletely reversible airway obstruction. This clinically heterogeneous group of patients is characterized by different phenotypes. Spirometry and clinical parameters, such as severity of dyspnea and exacerbation frequency, are used to diagnose and assess the severity of COPD. The purpose of this study was to investigate whether volatile organic compounds (VOCs) could be detected in the exhaled breath of patients with COPD and whether these VOCs could distinguish COPD patients from healthy subjects. Moreover, we aimed to investigate whether VOCs could be used as biomarkers for classifying patients into different subgroups of the disease. Ion mobility spectrometry was used to detect VOCs in the exhaled breath of COPD patients. One hundred and thirty-seven peaks were found to have a statistically significant difference between the COPD group and the combined healthy smokers and nonsmoker group. Six of these VOCs were found to correctly discriminate COPD patients from healthy controls with an accuracy of 70%. Only 15 peaks were found to be statistically different between healthy smokers and healthy nonsmokers. Furthermore, by determining the cutoff levels for each VOC peak, it was possible to classify the COPD patients into breathprint subgroups. Forced expiratory volume in 1 second, body mass index, and C-reactive protein seem to play a role in the discrepancies observed in the different breathprint subgroups.
Cell-cell and cell-extracellular matrix (ECM) adhesion regulates fundamental cellular functions and is crucial for cell-material contact. Adhesion is influenced by many factors like affinity and specificity of the receptor-ligand interaction or overall ligand concentration and density. To investigate molecular details of cell ECM and cadherins (cell-cell) interaction in vascular cells functional nanostructured surfaces were used Ligand-functionalized gold nanoparticles (AuNPs) with 6-8 nm diameter, are precisely immobilized on a surface and separated by non-adhesive regions so that individual integrins or cadherins can specifically interact with the ligands on the AuNPs. Using 40 nm and 90 nm distances between the AuNPs and functionalized either with peptide motifs of the extracellular matrix (RGD or REDV) or vascular endothelial cadherins (VEC), the influence of distance and ligand specificity on spreading and adhesion of endothelial cells (ECs) and smooth muscle cells (SMCs) was investigated. We demonstrate that RGD-dependent adhesion of vascular cells is similar to other cell types and that the distance dependence for integrin binding to ECM-peptides is also valid for the REDV motif. VEC-ligands decrease adhesion significantly on the tested ligand distances. These results may be helpful for future improvements in vascular tissue engineering and for development of implant surfaces.
A full understanding of the relationship between surface properties, protein adsorption, and immune responses is lacking but is of great interest for the design of biomaterials with desired biological profiles. In this study, polyelectrolyte multilayer (PEM) coatings with gradient changes in surface wettability were developed to shed light on how this impacts protein adsorption and immune response in the context of material biocompatibility. The analysis of immune responses by peripheral blood mononuclear cells to PEM coatings revealed an increased expression of proinflammatory cytokines tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1β, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 and the surface marker CD86 in response to the most hydrophobic coating, whereas the most hydrophilic coating resulted in a comparatively mild immune response. These findings were subsequently confirmed in a cohort of 24 donors. Cytokines were produced predominantly by monocytes with a peak after 24 h. Experiments conducted in the absence of serum indicated a contributing role of the adsorbed protein layer in the observed immune response. Mass spectrometry analysis revealed distinct protein adsorption patterns, with more inflammation-related proteins (e.g., apolipoprotein A-II) present on the most hydrophobic PEM surface, while the most abundant protein on the hydrophilic PEM (apolipoprotein A-I) was related to anti-inflammatory roles. The pathway analysis revealed alterations in the mitogen-activated protein kinase (MAPK)-signaling pathway between the most hydrophilic and the most hydrophobic coating. The results show that the acute proinflammatory response to the more hydrophobic PEM surface is associated with the adsorption of inflammation-related proteins. Thus, this study provides insights into the interplay between material wettability, protein adsorption, and inflammatory response and may act as a basis for the rational design of biomaterials.
Derzeit finden gravierende Veränderungen im Umfeld der Informations- und Kommunikationstechnik statt, die eine große Chance für die optimierte Prozessführung und Wertschöpfung mit darauf abgestimmten vernetzt kommunizierenden Sensoren bieten. Diese Art "smarter" Sensoren stellen Dienste innerhalb eines Netzwerks bereit und nutzen Informationen daraus. Dadurch ergibt sich aktuell die Notwendigkeit, die Anforderungen an Prozesssensoren sowie an deren Kommunikationsfähigkeiten detaillierter zu beschreiben – vom einfachen Temperatursensor bis über heute in Entwicklung befindlichen Messsystemen hinaus –, da diese Technologieentwicklungen rasant voranschreiten. Vernetzte Sensoren sind die Voraussetzung für die Realisierung von Cyberphysischen Produktionssystemen (CPPS) und zukünftiger Automatisierungskonzepte für die Prozessindustrie, wie sie auch durch das Zukunftsprojekt "Industrie 4.0" adressiert werden.
Die Technologie-Roadmap liefert darüber hinaus Perspektiven für Forschungs- und Entwicklungsförderung und gibt Ansätze für die Normungsarbeit. Sie wird damit auch für Politik, Industrieverbände und Gremien von Interesse sein. Wenn sich die Exzellenz der Forschung und das ausgeprägte Know-how der Gerätehersteller und Anwender zu Forschungskonsortien auf Augenhöhe zusammentun und das Wissen gemeinsam vorangebracht wird, kommen faire und gut durchdachte Technologietransferprojekte mit Sicherheit zum Erfolg. Neben der technologischen Weiterentwicklung der Prozesssensoren ist von Herstellern und Anwendern die hohe Verfügbarkeit der komplexen Technologie sicherzustellen, damit weiterhin Vertrauen in die Technik besteht – vom Anwender bis ins Management.
The article analyzes experimentally and theoretically the influence of microscope parameters on the pinhole-assisted Raman depth profiles in uniform and composite refractive media. The main objective is the reliable mapping of deep sample regions. The easiest to interpret results are found with low magnification, low aperture, and small pinholes. Here, the intensities and shapes of the Raman signals are independent of the location of the emitter relative to the sample surface. Theoretically, the results can be well described with a simple analytical equation containing the axial depth resolution of the microscope and the position of the emitter. The lower determinable object size is limited to 2–4 μm. If sub-micrometer resolution is desired, high magnification, mostly combined with high aperture, becomes necessary. The signal intensities and shapes depend now in refractive media on the position relative to the sample surface. This aspect is investigated on a number of uniform and stacked polymer layers, 2–160 μm thick, with the best available transparency. The experimental depth profiles are numerically fitted with excellent accuracy by inserting a Gaussian excitation beam of variable waist and fill fraction through the focusing lens area, and by treating the Raman emission with geometric optics as spontaneous isotropic process through the lens and the variable pinhole, respectively. The intersectional area of these two solid angles yields the leading factor in understanding confocal (pinhole-assisted) Raman depth profiles.
A laboratory prototype for hyperspectral imaging in ultra-violet (UV) region from 225 to 400 nm was developed and used to rapidly characterize active pharmaceutical ingredients (API) in tablets. The APIs are ibuprofen (IBU), acetylsalicylic acid (ASA) and paracetamol (PAR). Two sample sets were used for a comparison purpose. Sample set one comprises tablets of 100% API and sample set two consists of commercially available painkiller tablets. Reference measurements were performed on the pure APIs in liquid solutions (transmission) and in solid phase (reflection) using a commercial UV spectrometer. The spectroscopic part of the prototype is based on a pushbroom imager that contains a spectrograph and charge-coupled device (CCD) camera. The tablets were scanned on a conveyor belt that is positioned inside a tunnel made of polytetrafluoroethylene (PTFE) in order to increase the homogeneity of illumination at the sample position. Principal component analysis (PCA) was used to differentiate the hyperspectral data of the drug samples. The first two PCs are sufficient to completely separate all samples. The rugged design of the prototype opens new possibilities for further development of this technique towards real large-scale application.
Hypericin has large potential in modern medicine and exhibits fascinating structural dynamics, such as multiple conformations and tautomerization. However, it is difficult to study individual conformers/tautomers, as they cannot be isolated due to the similarity of their chemical and physical properties. An approach to overcome this difficulty is to combine single molecule experiments with theoretical studies. Time-dependent density functional theory (TD-DFT) calculations reveal that tautomerization of hypericin occurs via a two-step proton transfer with an energy barrier of 1.63 eV, whereas a direct single-step pathway has a large activation energy barrier of 2.42 eV. Tautomerization in hypericin is accompanied by reorientation of the transition dipole moment, which can be directly observed by fluorescence intensity fluctuations. Quantitative tautomerization residence times can be obtained from the autocorrelation of the temporal emission behavior revealing that hypericin stays in the same tautomeric state for several seconds, which can be influenced by the embedding matrix. Furthermore, replacing hydrogen with deuterium further proves that the underlying process is based on tunneling of a proton. In addition, the tautomerization rate can be influenced by a λ/2 Fabry–Pérot microcavity, where the occupation of Raman active vibrations can alter the tunneling rate.
An apparatus and method for analyzing a flow of material having an inlet region, a measurement range and an outlet region, and having a first diverter and a second diverter, and a deflection area, wherein in a first state of operation, the two diverters form a continuous first material flow space from the inlet region via the first diverter through the measurement range, via the second diverter to the outlet region, and in a second state of operation, form a continuous second material flow space from the inlet region via the first diverter through the deflection area, via the second diverter to the outlet region.
Die Erfindung betrifft eine Vorrichtung und Verfahren zur Analyse eines Materialstroms S mit einem Einlassbereich E, einem Messbereich M und einen Auslassbereich A sowie mit einer ersten Weiche W1 und einer zweiten Weiche W2 und einem Umlenkbereich U, wobei die beiden Weichen W1, W2 in einem ersten Schaltzustand Z1 einen durchgängigen ersten Materialdurchströmungsraum vom Einlassbereich E über die erste Weiche W1 durch den Messbereich M über die zweite Weiche W2 bis zum Auslassbereich A ausbilden und in einem zweiten Schaltzustand einen durchgängigen zweiten Materialdurchströmungsraum vom Einlassbereich E über die erste Weiche W1 durch den Umkenkbereich U über die zweite Weiche W2 bis zum Auslassbereich A ausbilden.
Die Erfindung betrifft eine Vorrichtung und Verfahren zur Analyse eines Materialstroms (S) mit einem Einlassbereich (E), einem Messbereich (M) und einen Auslassbereich (A) sowie mit einer ersten Weiche (W1) und einer zweiten Weiche (W2) und einem Umlenkbereich (U), wobei die beiden Weichen (W1, W2) in einem ersten Schaltzustand (Z1) einen durchgängigen ersten Materialdurchströmungsraum vom Einlassbereich (E) über die erste Weiche (W1) durch den Messbereich (M) über die zweite Weiche (W2) bis zum Auslassbereich (A) ausbilden und in einem zweiten Schaltzustand einen durchgängigen zweiten Materialdurchströmungsraum vom Einlassbereich (E) über die erste Weiche (W1) durch den Umlenkbereich (U) über die zweite Weiche (W2) bis zum Auslassbereich (A) ausbilden.
Die kontinuierliche Erfassung von Qualitätsparametern ist eine zunehmende Anforderung in der Polymerextrusion. Die optische Spektroskopie kann diese Anforderung erfüllen, da sie neben der Farbe weitere Parameter wie beispielsweise chemische Eigenschaften, Trübungsgrad oder Partikelgröße erfasst. Dabei werden für Inline-Messungen im Extruder optische Sonden eingesetzt. Im laufenden Betrieb bilden sich Ablagerungen auf den Sondenfenstern. Dieser Beitrag präsentiert ein neues Cleaning in Place Konzept, mit dessen Hilfe die Fenster auch während der Produktion ohne Unterbrechung gereinigt werden können. Auch die Kalibrierung der Messtechnik ist dabei möglich. Das verhindert Rüstzeiten und sichert eine kontinuierliche Inline-Messung.
Here, we report the continuous peroxide-initiated grafting of vinyltrimethoxysilane (VTMS) onto a standard polyolefin by means of reactive extrusion to produce a functionalized liquid ethylene propylene copolymer (EPM). The effects of the process parameters governing the grafting reaction and their synergistic interactions are identified, quantified and used in a mathematical model of the extrusion process. As process variables the VTMS and peroxide concentrations and the extruder temperature setting were systematically studied for their influence on the grafting and the relative grafting degree using a face-centered central composite design (FCD). The grafting degree was quantified by 1H NMR spectroscopy. Response surface methodology (RSM) was used to calculate the most efficient grafting process in terms of chemical usage and graft yield. With the defined processing window, it was possible to make precise predictions about the grafting degree with at the same time highest possible relative degree of grafting.
Ion Mobility Spectrometry (IMS) is a widely used and `well-known’ technique of ion separation in the gaseous phase based on the differences in ion mobilities under an electric field. All IMS instruments operate with an electric field that provides space separation, but some IMS instruments also operate with a drift gas flow that provides also a temporal separation. In this review we will summarize the current IMS instrumentation. IMS techniques have received an increased interest as new instrumentation and have become available to be coupled with mass spectrometry (MS). For each of the eight types of IMS instruments reviewed it is mentioned whether they can be hyphenated with MS and whether they are commercially available. Finally, out of the described devices, the six most-consolidated ones are compared. The current review article is followed by a companion review article which details the IMS hyphenated techniques (mainly gas chromatography and mass spectrometry) and the factors that make the data from an IMS device change as a function of device parameters and sampling conditions. These reviews will provide the reader with an insightful view of the main characteristics and aspects of the IMS technique.
Ion Mobility Spectrometry (IMS) is a widely used and ‘well-known’ technique of ion separation in the gaseous phase based on the differences of ion mobilities under an electric field. This technique has received increased interest over the last several decades as evidenced by the pace and advances of new IMS devices available. In this review we explore the hyphenated techniques that are used with IMS, specifically mass spectrometry as an identification approach and a multi-capillary column as a pre-separation approach. Also, we will pay special attention to the key figures of merit of the ion mobility spectrum and how data sets are treated, and the influences of the experimental parameters on both conventional drift time IMS (DTIMS) and miniaturized IMS also known as high Field Asymmetric IMS (FAIMS) in the planar configuration. The present review article is preceded by a companion review article which details the current instrumentation and contains the sections that configure both conventional DTIMS and FAIMS devices. These reviews will give the reader an insightful view of the main characteristics and aspects of the IMS technique.
Highly viscous bioinks offer great advantages for the three-dimensional fabrication of cell-laden constructs by microextrusion printing. However, no standardised method of mixing a high viscosity biomaterial ink and a cell suspension has been established so far, leading to non-reproducible printing results. A novel method for the homogeneous and reproducible mixing of the two components using a mixing unit connecting two syringes is developed and investigated. Several static mixing units, based on established mixing designs, were adapted and their functionality was determined by analysing specific features of the resulting bioink. As a model system, we selected a highly viscous ink consisting of fresh frozen human blood plasma, alginate, and methylcellulose, and a cell suspension containing immortalized human mesenchymal stem cells. This bioink is crosslinked after fabrication. A pre-crosslinked gellan gum-based bioink providing a different extrusion behaviour was introduced to validate the conclusions drawn from the model system. For characterisation, bioink from different zones within the mixing device was analysed by measurement of its viscosity, shape fidelity after printing and visual homogeneity. When taking all three parameters into account, a comprehensive and reliable comparison of the mixing quality was possible. In comparison to the established method of manual mixing inside a beaker using a spatula, a significantly higher proportion of viable cells was detected directly after mixing and plotting for both bioinks when the mixing unit was used. A screw-like mixing unit, termed “HighVisc”, was found to result in a homogenous bioink after a low number of mixing cycles while achieving high cell viability rates.
Appropriate mechanical properties and fast endothelialization of synthetic grafts are key to ensure long-term functionality of implants. We used a newly developed biostable polyurethane elastomer (TPCU) to engineer electrospun vascular scaffolds with promising mechanical properties (E-modulus: 4.8 ± 0.6 MPa, burst pressure: 3326 ± 78 mmHg), which were biofunctionalized with fibronectin (FN) and decorin (DCN). Neither uncoated nor biofunctionalized TPCU scaffolds induced major adverse immune responses except for minor signs of polymorph nuclear cell activation. The in vivo endothelial progenitor cell homing potential of the biofunctionalized scaffolds was simulated in vitro by attracting endothelial colony-forming cells (ECFCs). Although DCN coating did attract ECFCs in combination with FN (FN + DCN), DCN-coated TPCU scaffolds showed a cell-repellent effect in the absence of FN. In a tissue-engineering approach, the electrospun and biofunctionalized tubular grafts were cultured with primary-isolated vascular endothelial cells in a custom-made bioreactor under dynamic conditions with the aim to engineer an advanced therapy medicinal product. Both FN and FN + DCN functionalization supported the formation of a confluent and functional endothelial layer.
Medical implants play a central role in modern medicine and both, naturally derived and synthetic materials have been explored as biomaterials for such devices. However, when implanted into living tissue, most materials initiate a host response. In addition, implants often cause bacterial infections leading to complications. Polyelectrolyte multilayer (PEM) coatings can be used for functionalization of medical implants improving the implant integration and reducing foreign body reactions. Some PEMs are also known to show antibacterial properties. We developed a PEM coating suggesting that it can decrease the risk of bacterial infections occurring after implantation while being highly biocompatible. We applied two different standard tests for evaluating the PEM’s antibacterial properties, the ISO norm (ISO 22196) and one ASTM norm (ASTM E2180) test. We found a reduction of bacterial growth on the PEM but to a different degree depending on the testing method. This result demonstrates the need for defining proper method to evaluate antibacterial properties of surface coatings.
Porous silica materials are often used for drug delivery. However, systems for simultaneous delivery of multiple drugs are scarce. Here we show that anisotropic and amphiphilic dumbbell core–shell silica microparticles with chemically selective environments can entrap and release two drugs simultaneously. The dumbbells consist of a large dense lobe and a smaller hollow hemisphere. Electron microscopy images show that the shells of both parts have mesoporous channels. In a simple etching process, the properly adjusted stirring speed and the application of ammonium fluoride as etching agent determine the shape and the surface anisotropy of the particles. The surface of the dense lobe and the small hemisphere differ in their zeta potentials consistent with differences in dye and drug entrapment. Confocal Raman microscopy and spectroscopy show that the two polyphenols curcumin (Cur) and quercetin (QT) accumulate in different compartments of the particles. The overall drug entrapment efficiency of Cur plus QT is high for the amphiphilic particles but differs widely between Cur and QT compared to controls of core–shell silica microspheres and uniformly charged dumbbell microparticles. Furthermore, Cur and QT loaded microparticles show different cancer cell inhibitory activities. The highest activity is detected for the dual drug loaded amphiphilic microparticles in comparison to the controls. In the long term, amphiphilic particles may open up new strategies for drug delivery.
The transmembrane Ca2+ − activated Cl− channel - human bestrophin-1 (hBest1) is expressed in retinal pigment epithelium and mutations of BEST1 gene cause ocular degenerative diseases colectivelly referred to as “bestrophinopathies”. A large number of genetical, biochemical, biophysical and molecular biological studies have been performed to understand the relationship between structure and function of the hBest1 protein and its pathophysiological significance. Here, we review the current understanding of hBest1 surface organization, interactions with membrane lipids in model membranes, and its association with microdomains of cellular membranes. These highlights are significant for modulation of channel activity in cells.
The critical process parameters cell density and viability during mammalian cell cultivation are assessed by UV/VIS spectroscopy in combination with multivariate data analytical methods. This direct optical detection technique uses a commercial optical probe to acquire spectra in a label-free way without signal enhancement. For the cultivation, an inverse cultivation protocol is applied, which simulates the exponential growth phase by exponentially replacing cells and metabolites of a growing Chinese hamster ovary cell batch with fresh medium. For the simulation of the death phase, a batch of growing cells is progressively replaced by a batch with completely starved cells. Thus, the most important parts of an industrial batch cultivation are easily imitated. The cell viability was determined by the well-established method partial least squares regression (PLS). To further improve process knowledge, the viability has been determined from the spectra based on a multivariate curve resolution (MCR) model. With this approach, the progress of the cultivations can be continuously monitored solely based on an UV/VIS sensor. Thus, the monitoring of critical process parameters is possible inline within a mammalian cell cultivation process, especially the viable cell density. In addition, the beginning of cell death can be detected by this method which allows us to determine the cell viability with acceptable error. The combination of inline UV/VIS spectroscopy with multivariate curve resolution generates additional process knowledge complementary to PLS and is considered a suitable process analytical tool for monitoring industrial cultivation processes.
Foam has been employed as an improved or enhanced oil recovery method to overcome gravity override and the channeling and fingering of the injected gas, which arises because of the low density and viscosity of the injected fluid combined with the rock heterogeneity. A major challenge, however, is the stability of the generated foam when it contacts the oil. In this study we investigate the feasibility of using inexpensive nanoparticles made of coal fly ash, an abundantly available waste product of coal power plants, as a foam booster. We investigate the viability of reducing the size of fly ash particles to 100−200 nm using high-frequency ultrasonic grinding. We also study the foaminess (foamability), strength, and stability of the foams made with minor concentrations of fly ash nanoparticles and surfactant, both in bulk and porous media. The effect of monovalent and divalent ion concentration on the foaminess of the nanoash suspension combined with very low concentrations of a commercial alpha olefin sulfonate (AOS) surfactant, in the presence and absence of oil, is studied. We observe that bulk foam that contains very small amounts of nanoash particles shows a higher stability in the presence of model oils. Furthermore, experiments in porous media exhibit remarkably stronger foam with mixtures of nanoash and surfactant, such that the amount of produced liquids from the cores significantly increases. For the first time we show that nanoash can be used to stabilize nitrogen foam in the presence of crude oil at high temperature and pressure. In the presence of oil, the nanoash−AOS foam shows a higher stability, although crude oil tends to form stable emulsions in water in the presence of nanoash.
Ecuador, traditionally an agricultural based economy, has a great potential for valorizing their industrial residues. This study, presents a techno-economic analysis for applying a novel biomass oxidation method to produce formic and acetic acids from coffee husk residues in Machala, Ecuador. The analysis determined that the time of return of investment was lower than 5 years, making this project economically feasible, when producing approx. 1000 tons of formic acid per year, which is enough for supplying the Ecuadorian market. This production, would reduce imports costs and develop the chemical industry in the country.
Programmable nano-bio interfaces driven by tuneable vertically configured nanostructures have recently emerged as a powerful tool for cellular manipulations and interrogations. Such interfaces have strong potential for ground-breaking advances, particularly in cellular nanobiotechnology and mechanobiology. However, the opaque nature of many nanostructured surfaces makes non-destructive, live-cell characterization of cellular behavior on vertically aligned nanostructures challenging to observe. Here, a new nanofabrication route is proposed that enables harvesting of vertically aligned silicon (Si) nanowires and their subsequent transfer onto an optically transparent substrate, with high efficiency and without artefacts. We demonstrate the potential of this route for efficient live-cell phase contrast imaging and subsequent characterization of cells growing on vertically aligned Si nanowires. This approach provides the first opportunity to understand dynamic cellular responses to a cell-nanowire interface, and thus has the potential to inform the design of future nanoscale cellular manipulation technologies.
To correctly assess the cleanliness of technical surfaces in a production process, corresponding online monitoring systems must provide sufficient data. A promising method for fast, large-area, and non-contact monitoring is hyperspectral imaging (HSI), which was used in this paper for the detection and quantification of organic surface contaminations. Depending on the cleaning parameter constellation, different levels of organic residues remained on the surface. Afterwards, the cleanliness was determined by the carbon content in the atom percent on the sample surfaces, characterized by XPS and AES. The HSI data and the XPS measurements were correlated, using machine learning methods, to generate a predictive model for the carbon content of the surface. The regression algorithms elastic net, random forest regression, and support vector machine regression were used. Overall, the developed method was able to quantify organic contaminations on technical surfaces. The best regression model found was a random forest model, which achieved an R2 of 0.7 and an RMSE of 7.65 At.-% C. Due to the easy-to-use measurement and the fast evaluation by machine learning, the method seems suitable for an online monitoring system. However, the results also show that further experiments are necessary to improve the quality of the prediction models.
Employing diffuse reflection ultraviolet visible (UV–Vis) spectroscopy we developed an approach that is capable to quantitatively determine flux residues on a technical copper surface. The technical copper surface was soldered with a no-clean flux system of organic acids. By a post-solder cleaning step with different cleaning parameters, various levels of residues were produced. The surface was quantitatively and qualitatively characterized using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), Fourier transform infrared spectroscopy (FTIR) and diffuse reflection UV–Vis spectroscopy. With the use of a multivariate analysis (MVA) we examined the UV–Vis data to create a correlation to the carbon content on the surface. The UV–Vis data could be discriminated for all groups by their level of organic residues. Combined with XPS the data were evaluated by a partial least squares (PLS) regression to establish a model. Based on this predictive model, the carbon content was calculated with an absolute error of 2.7 at.%. Due to the high correlation of predictive model, the easy-to-use measurement and the evaluation by multivariate analysis the developed method seems suitable for an online monitoring system. With this system, flux residues can be detected in a manufacturing cleaning process of technical surfaces after soldering.
High-performance liquid chromatography is one of the most important analytical tools for the identification and separation of substances. The efficiency of this method is largely determined by the stationary phase of the columns. Although monodisperse mesoporous silica microspheres (MPSM) represent a commonly used material as stationary phase their tailored preparation remains challenging. Here we report on the synthesis of four MPSMs via the hard template method. Silica nanoparticles (SNPs) which form the silica network of the final MPSMs were generated in situ from tetraethyl orthosilicate (TEOS) in the presence of (3-aminopropyl) triethoxysilane (APTES) functionalized p(GMA-co-EDMA) as hard template. Methanol, ethanol, 2-propanol, and 1-butanol were applied as solvents to control the size of the SNPs in the hybrid beads (HB). After calcination, MPSMs with different sizes, morphology and pore properties were obtained and characterized by scanning electron microscopy, nitrogen adsorption and desorption measurements, thermogravimetric analysis, solid state NMR and DRIFT IR spectroscopy. Interestingly, the 29Si NMR spectra of the HBs show T and Q group species which suggests that there is no covalent linkage between the SNPs and the template. The MPSMs were functionalized with trimethoxy (octadecyl) silane and used as stationary phases in reversed-phase chromatography to separate a mixture of eleven different amino acids. The separation characteristics of the MPSMs strongly depend on their morphology and pore properties which are controlled by the solvent during the preparation of the MPSMs. Overall, the separation behavior of the best phases is comparable with those of commercially available columns. The phases even achieve faster separation of the amino acids without loss of quality.
Mesoporous silica microspheres (MPSMs) find broad application as separation materials in high liquid chromatography (HPLC). A promising preparation strategy uses p(GMA-co-EDMA) as hard templates to control the pore properties and a narrow size distribution of the MPMs. Here six hard templates were prepared which differ in their porosity and surface functionalization. This was achieved by altering the ratio of GMA to EDMA and by adjusting the proportion of monomer and porogen in the polymerization process. The various amounts of GMA incorporated into the polymer network of P1-6 lead to different numbers of tetraethylene pentamine in the p(GMA-co-EDMA) template. This was established by a partial least squares regression (PLS-R) model, based on FTIR spectra of the templates. Deposition of silica nanoparticles (SNP) into the template under Stoeber conditions and subsequent removal of the polymer by calcination result in MPSM1-6. The size of the SNPs and their incorporation depends on the pore parameters of the template and degree of TEPA functionalization. Moreover, the incorporated SNPs construct the silica network and control the pore parameters of the MPSMs. Functionalization of the MPSMs with trimethoxy (octadecyl) silane allows their use as a stationary phase for the separation of biomolecules. The pore characteristics and the functionalization of the template determine the pore structure of the silica particles and, consequently, their separation properties.
The hard template method for the preparation of monodisperse mesoporous silica microspheres (MPSMs) has been established in recent years. In this process, in situ-generated silica nanoparticles (SNPs) enter the porous organic template and control the size and pore parameters of the final MPSMs. Here, the sizes of the deposited SNPs are determined by the hydrolysis and condensation rates of different alkoxysilanes in a base catalyzed sol–gel process. Thus, tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS) and tetrabutyl orthosilicate (TBOS) were sol–gel processed in the presence of amino-functionalized poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) (p(GMA-co-EDMA)) templates. The size of the final MPSMs covers a broad range of 0.5–7.3 µm and a median pore size distribution from 4.0 to 24.9 nm. Moreover, the specific surface area can be adjusted between 271 and 637 m2 g−1. Also, the properties and morphology of the MPSMs differ according to the SNPs. Furthermore, the combination of different alkoxysilanes allows the individual design of the morphology and pore parameters of the silica particles. Selected MPSMs were packed into columns and successfully applied as stationary phases in high-performance liquid chromatography (HPLC) in the separation of various water-soluble vitamins.
Bioactive cations, including calcium, copper and magnesium, have shown the potential to become the alternative to protein growth factor-based therapeutics for bone healing. Ion substitutions are less costly, more stable, and more effective at low concentrations. Although they have been shown to be effective in providing bone grafts with more biological functions, the precise control of ion release kinetics is still a challenge. Moreover, the synergistic effect of three or more metal ions on bone regeneration has rarely been studied. In this study, vaterite-calcite CaCO3 particles were loaded with copper (Cu2+) and magnesium (Mg2+). The polyelectrolyte multilayer (PEM) was deposited on CaCuMg-CO3 particles via layer-by-layer technique to further improve the stability and biocompatibility of the particles and to enable controlled release of multiple metal ions. The PEM coated microcapsules were successfully combined with collagen at the outmost layer, providing a further stimulating microenvironment for bone regeneration. The in vitro release studies showed remarkably stable release of Cu2+ in 2 months without initial burst release. Mg2+ was released in relatively low concentration in the first 7 days. Cell culture studies showed that CaCuMg-PEM-Col microcapsules stimulated cell proliferation, extracellular maturation and mineralization more effectively than blank control and other microcapsules without collagen adsorption (Ca-PEM, CaCu-PEM, CaMg-PEM, CaCuMg-PEM). In addition, the CaCuMg-PEM-Col microcapsules showed positive effects on osteogenesis and angiogenesis in gene expression studies. The results indicate that such a functional and controllable delivery system of multiple bioactive ions might be a safer, simpler and more efficient alternative of protein growth factor-based therapeutics for bone regeneration. It also provides an effective method for functionalizing bone grafts for bone tissue engineering.
The analysis of exhaled metabolites has become a promising field of research in recent decades. Several volatile organic compounds reflecting metabolic disturbance and nutrition status have even been reported. These are particularly important for long-term measurements, as needed in medical research for detection of disease progression and therapeutic efficacy. In this context, it has become urgent to investigate the effect of fasting and glucose treatment for breath analysis. In the present study, we used amodel of ventilated rats that fasted for 12 h prior to the experiment. Ten rats per group were randomly assigned for continuous intravenous infusion without glucose or an infusion including 25 mg glucose per 100 g per hour during an observation period of 12 h. Exhaled gas was analysed using multicapillary column ion-mobility spectrometry. Analytes were identified by the BS-MCC/IMS database (version 1209; B & S Analytik, Dortmund, Germany). Glucose infusion led to a significant increase in blood glucose levels (p<0.05 at 4 h and thereafter) and cardiac output (p<0.05 at 4 h and thereafter). During the observation period, 39 peaks were found collectively. There were significant differences between groups in the concentration of ten volatile organic compounds: p<0.001 at 4 h and thereafter for isoprene, cyclohexanone, acetone, p-cymol, 2-hexanone, phenylacetylene, and one unknown compound, and p<0.001 at 8 h and thereafter for 1-pentanol, 1-propanol, and 2-heptanol. Our results indicate that for long-term measurement, fasting and the withholding of glucose could contribute to changes of volatile metabolites in exhaled air.
Background: Multicapillary column ion-mobility spectrometry (MCC-IMS) may identify volatile components in exhaled gas. The authors therefore used MCC-IMS to evaluate exhaled gas in a rat model of sepsis, inflammation, and hemorrhagic shock.
Methods: Male Sprague-Dawley rats were anesthetized and ventilated via tracheostomy for 10 h or until death. Sepsis was induced by cecal ligation and incision in 10 rats; a sham operation was performed in 10 others. In 10 other rats, endotoxemia was induced by intravenous administration of 10 mg/kg lipopolysaccharide. In a final 10 rats, hemorrhagic shock was induced to a mean arterial pressure of 35 +/- 5 mmHg. Exhaled gas was analyzed with MCC-IMS, and volatile compounds were identified using the BS-MCC/IMS-analytes database (Version 1209; B&S Analytik, Dortmund, Germany).
Results: All sham animals survived the observation period, whereas mean survival time was 7.9 h in the septic animals, 9.1 h in endotoxemic animals, and 2.5 h in hemorrhagic shock. Volatile compounds showed statistically significant differences in septic and endotoxemic rats compared with sham rats for 3-pentanone and acetone. Endotoxic rats differed significantly from sham for 1-propanol, butanal, acetophenone, 1,2-butandiol, and 2-hexanone. Statistically significant differences were observed between septic and endotoxemic rats for butanal, 3-pentanone, and 2-hexanone. 2-Hexanone differed from all other groups in the rats with shock.
Conclusions: Breath analysis of expired organic compounds differed significantly in septic, inflammation, and sham rats. MCC-IMS of exhaled breath deserves additional study as a noninvasive approach for distinguishing sepsis from inflammation.
Modifying the natural characteristics of PLA 3D-printed models is of interest in various research areas in which 3D-printing is applied. Thus, in this study, we describe the simple impregnation of FDM 3D-printed PLA samples with well-defined silver nanoparticles and an iron metal salt. Quasi-spherical and dodecahedra silver particles were strongly attached at the channels of 3D-printed milli-fluidic reactors to demonstrate their attachment and interaction with the flow, as an example. Furthermore, Fenton-like reactions were successfully developed by an iron catalyst impregnated in 3D-printed stirrer caps to induce the degradation of a dye and showed excellent reproducibility.
We report on the cure characterization, based on inline monitoring of the dielectric parameters, of a commercially available epoxy phenol resin molding compound with a high glass transition temperature (>195 °C), which is suitable for the direct packaging of electronic components. The resin was cured under isothermal temperatures close to general process conditions (165–185 °C). The material conversion was determined by measuring the ion viscosity. The change of the ion viscosity as a function of time and temperature was used to characterize the cross-linking behavior, following two separate approaches (model based and isoconversional). The determined kinetic parameters are in good agreement with those reported in the literature for EMCs and lead to accurate cure predictions under process-near conditions. Furthermore, the kinetic models based on dielectric analysis (DEA) were compared with standard offline differential scanning calorimetry (DSC) models, which were based on dynamic measurements. Many of the determined kinetic parameters had similar values for the different approaches. Major deviations were found for the parameters linked to the end of the reaction where vitrification phenomena occur under process-related conditions. The glass transition temperature of the inline molded parts was determined via thermomechanical analysis (TMA) to confirm the vitrification effect. The similarities and differences between the resulting kinetics models of the two different measurement techniques are presented and it is shown how dielectric analysis can be of high relevance for the characterization of the curing reaction under conditions close to series production.
In vivo, cells encounter different physical and chemical signals in the extracellular matrix (ECM) which regulate their behavior. Examples of these signals are micro- and nanometer-sized features, the rigidity, and the chemical composition of the ECM. The study of cell responses to such cues is important to understand complex cell functions, some diseases, and is basis for the development of new biomaterials for applications in medical implants or regenerative medicine. Therefore, the development of new methods for surface modifications with controlled physical and chemical features is crucial. In this work, we report a new combination of micelle nanolithography (BCML) and soft micro-lithography, for the production of polyethylene glycol (PEG) hydrogels, with a micro-grooved surface and decoration with hexagonally precisely arranged gold nanoparticles (AU NPs). The Au-NPs are used for binding adhesive ligands in a well-defined density. First tests were performed by culturing human fibroblasts on the gels. Adhesion and alignment of the cells along the parallel grooves of the surface were investigated. The substrates could provide a new platform for studying cell contact guidance by micro structures, and may enable a more precise control of cell behavior by nanometrically controlled surface functionalization.
Surface topographies are often discussed as an important parameter influencing basic cell behavior. Whereas most in vitro studies deal with microstructures with sharp edges, smooth, curved microscale topographies might be more relevant concerning in-vivo situations. Addressing the lack of highly defined surfaces with varying curvature, we present a topography chip system with 3D curved features of varying spacing, curvature radii as well as varying overall dimensions of curved surfaces. The CurvChip is produced by low-cost photolithography with thermal reflow, subsequent (repetitive) PDMS molding and hot embossing. The platform facilitates the systematic in-vitro investigation of the impact of substrate curvature on cell types like epithelial, endothelial, smooth muscle cells, or stem cells. Such investigations will not only help to further understand the mechanism of curvature sensation but may also contribute to optimize cell-material interactions in the field of regenerative medicine.
Polyelectrolyte multilayer (PEM) are thin polymeric films produced by alternating adsorption of positively and negatively charged polyelectrolytes (PE) on a substrate. These films are considered drug delivery agents as well as coating material for implants, due to their antibiofouling and biologically benign properties. For these reasons the film mechanical properties as well as response to mechanical stress are important measurement parameters. Especially intriguing is the correlation of the mechanical properties of PEM on macroscopic level with the structure of PEM on molecular level, which is addressed here for the first time. This study investigates PEM from PDADMA/PSS produced by spraying technique with neutron and X-ray reflectometry. Reflectometry technique provides precise information on thickness and density (i.e., electron density or scattering length density, respectively), and, this way, allows to conclude on changes in film composition. Thus, neutron and X-ray reflectometry technique is suitable to investigate the overall and the internal transformations, which PEM films might undergo upon exposure to mechanical load. During uniaxial elongation two regimes of PEM deformation can be observed: An elastic regime at small elongations (below ca. 0.2%), which is characterized by a reversible change of film thickness, and a plastic regime with a permanent change above this limit. Both regimes have in common, that the mechanical load induces an increase of the film thickness, which is accompanied by an uptake of water from the surrounding atmosphere. The strain causes a molecular rearrangement within the PEM-structure of stratified layers, which, even in elastic regime, is permanent, although the thickness change remains reversible.
Reflectometry is known since long as an interferometric method which can be used to characterize surfaces and thin films regarding their structure and,to a certain degree,composition as well.Properties like layer structures,layer thickness,density,and interface roughness can be determined by fitting the obtained reflectivity data with an appropriate model using a recursive fitting routine. However,one major drawback of the reflectometric method is its restriction to planar surfaces.In this article we demonstrate an approach to apply X-ray and neutron reflectometry to curved surfaces by means of the example of bent bare and coated glass slides.We prove the possibility to observe all features like Fresnel decay,Kiessig fringes,Bragg peaks and off-specular scattering and are able to interpret the data using common fitting software and to derive quantitative results about roughness,layer thickness and internal structure. The proposed method has become practical due to the availability of high quality 2D-detectors. It opens up the option to explore many kinds and shapes of samples,which,due to their geometry,have not been in the focus of reflectometry techniques until now.
Children undergoing systemic chemotherapy often suffer from severe immunosuppression usually associated to severe neutropenia (neutrophils < 0.5 x 109/l). Clinical courses during those periods range from asymptomatic to septic general conditions. Development of septic symptoms can be very fast and life-threatening. Swift detection of risk factors in those patients is therefore needed. So far no early, rapid and reliable marker or tool exists. Ion-Mobility-Spectrometry coupled with a Multi-Capillary-Column (IMS-MCC) can analyze more than 600 volatile components from exhaled air within a few minutes and hence is a potential, rapid detection-tool. As a proof of concept we measured the exhaled breath of 11 patients with neutropenia and 10 healthy controls ranging from 3 to 18 years of age at the time of measurement. Ten milliliters breath samples were taken at the outpatient clinic and analyzed with an onsite IMS-MCC (BreathDiscovery, B&S Analytik, Dortmund, Germany). Dead-space-volume was adapted to two groups (small 250 ml, large 500 ml). Interestingly 59 differing peaks were measured. Eleven were significantly different (p ≤ 0.05), three of which highly significant (p ≤ 0.01) in Mann-Whitney-Rank-Sum-testing. The corresponding analytes used in the decision tree are 2-Propanol, D-Limonene and Acetone. The analytes with the lowest rank sum identified are 2-Hexanone, Iso-Propylamine and 1-Butanol. Eventually we were able to show a three-step-decision-tree, which discerns the 21 samples except one from each group. Sensitivity was 90 % and specificity was 91 %. Naturally these findings need further confirmation within a bigger population. Our pilot-study proves that Ion-Mobility-Spectrometry coupled with a Multi-Capillary-Column is a feasible rapid diagnostic tool in the setting of a pediatric oncology out-patient clinic for patients 3 years and older. Our first results furthermore encourage additional analysis as to whether patients at risk for septic events during immunosuppression can be diagnosed in advance by rapidly assessing risk factors such as Neutropenia in exhaled breath.
The present study investigated the possibilities and limitations of using a low-cost NIR spectrometer for the verification of the presence of the declared active pharmaceutical ingredients (APIs) in tablet formulations, especially for medicine screening studies in low-resource settings. Spectra from 950 to 1650 nm were recorded for 170 pharmaceutical products representing 41 different APIs, API combinations or placebos. Most of the products, including 20 falsified medicines, had been collected in medicine quality studies in African countries. After exploratory principal component analysis, models were built using data-driven soft independent modelling of class analogy (DD-SIMCA), a one-class classifier algorithm, for tablet products of penicillin V, sulfamethoxazole/trimethoprim, ciprofloxacin, furosemide, metronidazole, metformin, hydrochlorothiazide, and doxycycline. Spectra of amoxicillin and amoxicillin/clavulanic acid tablets were combined into a single model. Models were tested using Procrustes cross-validation and by projection of spectra of tablets containing the same or different APIs. Tablets containing no or different APIs could be identified with 100 % specificity in all models. A separation of the spectra of amoxicillin and amoxicillin/clavulanic acid tablets was achieved by partial least squares discriminant analysis. 15 out of 19 external validation products (79 %) representing different brands of the same APIs were correctly identified as members of the target class; three of the four rejected samples showed an API mass percentage of the total tablet weight that was out of the range covered in the respective calibration set. Therefore, in future investigations larger and more representative spectral libraries are required for model building. Falsified medicines containing no API, incorrect APIs, or grossly incorrect amounts of the declared APIs could be readily identified. Variation between different NIR-S-G1 spectroscopic devices led to a loss of accuracy if spectra recorded with different devices were pooled. Therefore, piecewise direct standardization was applied for calibration transfer. The investigated method is a promising tool for medicine screening studies in low-resource settings.
Highly active MgP catalyst for biodiesel production and polyethylene terephthalate depolymerization
(2022)
A highly active heterogeneous catalyst was designed and employed for two relevant transesterification reactions. i. e. biodiesel production and depolymerization of polyethylene terephthalate (PET). The material was prepared in the presence of pectin by the co-precipitation method followed by calcination at 600°C (MgP). MgP is efficient for biodiesel production, with a yield of ≈99% in 6 h/65°C, and with a molar ratio methanol: oil of 21:1. The reference material (MgR, prepared in absence of pectin) showed a poor catalytic performance in the same experimental conditions. For the methanolysis of PET, 100% PET conversion was obtained with 3 wt% catalyst, 200:1 methanol: PET molar ratio at milder conditions 160°C/4 h, compared to a 33% conversion without the presence of a catalyst. The catalyst showed remarkable stability and negligible deactivation after five consecutive runs. Materials were characterized by SEM, XRD, IR, TGA, and BET.
Concrete is significant for construction. A problem in application is the appearance of cracks that will damage its strength. An autogenous crack-healing mechanism based on bacteria receives increasing attention in recent years. The bacteria are able to form calcium carbonate (CaCO3) precipitations in suitable conditions to protect and reinforce the concrete. However, a large number of spores are crushed in aged specimens, resulting in a loss of viability. A new kind of hydrogel crosslinked by alginate, chitosan and calcium ions was introduced in this study. It was observed that the addition of chitosan improved the swelling properties of calcium alginate. Opposite pH response to calcium alginate was observed when the chitosan content in the solution reached 1.0%. With an addition of 1.0% chitosan in hydrogel beads, 10.28% increase of compressive strength and 13.79% increase of flexural strength to the control were observed. The results reveal self-healing properties of concretes. A healing crack of 4 cm length and 1 mm width was observed when using cement PO325, with the addition of bacterial spores (2.54–3.07 × 105/cm3 concrete) encapsulated by hydrogel containing no chitosan.
This book investigates and highlights the most critical challenges the pharmaceutical industry faces in an increasingly competitive environment of inflationary R&D investments and tightening cost control pressures. The authors present three sources of pharmaceutical innovation: new management methods in the drug development pipeline; new technologies as enablers for cutting-edge R&D; and new forms of cooperation and internationalization, such as open innovation in the early phases of R&D. New models and methods are illustrated with cases from Europe, the US, and Asia. This third fully revised edition was expanded to reflect the latest updates in open and collaborative innovation, the greater strategic importance of venture capital and early stage investments, and the new range of emerging technologies now being put to use in pharmaceutical innovation.
The surface properties of human meibomian lipids (MGS), the major constituent of the tear film (TF) lipid layer, are of key importance for TF stability. The dynamic interfacial properties of films by MGS from normal eyes (nMGS) and eyes with meibomian gland dysfunction (dMGS) were studied using a Langmuir surface balance. The behavior of the samples during dynamic area changes was evaluated by surface pressure–area isotherms and isocycles. The surface dilatational rheology of the films was examined in the frequency range 10−5 to 1 Hz by the stress-relaxation method. A significant difference was found, with dMGS showing slow viscosity-dominated relaxation at 10−4 to 10−3 Hz, whereas nMGS remained predominantly elastic over the whole range. A Cole–Cole plot revealed two characteristic processes contributing to the relaxation, fast (on the scale of characteristic time τ < 5 s) and slow (τ > 100 s), the latter prevailing in dMGS films. Brewster angle microscopy revealed better spreading of nMGS at the air–water interface, whereas dMGS layers were non-uniform and patchy. The distinctions in the interfacial properties of the films in vitro correlated with the accelerated degradation of meibum layer pattern at the air–tear interface and with the decreased stability of TF in vivo. These results, and also recent findings on the modest capability of meibum to suppress the evaporation of the aqueous subphase, suggest the need for a re-evaluation of the role of MGS. The probable key function of meibomian lipids might be to form viscoelastic films capable of opposing dilation of the air–tear interface. The impact of temperature on the meibum surface properties is discussed in terms of its possible effect on the normal structure of the film.
We investigate the toxicity of different types and sizes of microplastic particles (0.3–4 mm) under different conditions (new particles, aged particles with biofilm, and particles with adsorbed Tributyltin) on the freshwater amphipod Gammarus fossarum in 3-week exposures. All types of plastic particles, which were randomly taken up to a small extent, were mostly Polyphenylenoxide, Polybutylentherephthalate and Polypropylene, with particles < 1 mm in size. Plastic particles did not affect the feeding and locomotory behaviour of gammarids, and there was no strong difference between pristine plastic particles and aged particles with biofilm. Mortality tended to be higher compared with the control. Tributyltinhydride (TBTH) adsorbed to microplastic particles had no effect on uptake, survival, feeding and locomotory behaviour during the 3 weeks of exposure. Dissolved TBTH, however, was already very toxic after few days of exposure (LC50-96h < 1 ng l–1).
Primäres Ziel und Aufgabe dieser Arbeit ist ... die Entwicklung einer neuen Recyclingmethode für PET, die die Nachteile der bisherigen Verwertungsmethoden vermeidet und unter weitgehendem Erhalt der bereits erbrachten Syntheseleistung definierte Oligomere liefert. Aus diesen können in Folge hochwertige Produkte hergestellt werden.
Clay minerals play an increasingly important role as functional fillers and reinforcing materials for clay polymer nanocomposites (CPN) in advanced applications. Among the prerequisites necessary for polymer improvement by clay minerals are homogeneous and stable Distribution of the clay mineral throughout the CPN, good compatibility of the reinforcement with the Matrix component and suitable processability. Typically, clay minerals are surface-modified with organic interface active compounds like detergents or silanes to obtain favorable properties as filler. They are incorporated into the polymer matrix using manufacturing Equipment like extruders, batch reactors or other mixing machines. In order for the surface modification to survive the stresses and strains during incorporation, the modified clay minerals must display sufficient thermal and mechanical stability to retain the compatibilizing effect. In the present study, thermogravimetry was used in combination with isoconversional kinetic analysis to determine the thermal stability of a silane-modified clay mineral based on bentonite. These findings were compared with the stability of the same clay mineral that was only surfactant-modified. It was found that silane modification leads to significantly improved thermal stability, which depends strongly on the type of silane employed.
Recycling of poly(ethylene terephthalate) (PET) is of crucial importance, since worldwide amounts of PETwaste increase rapidly due to its widespread applications. Hence, several methods have been developed, like energetic, material, thermo-mechanical and chemical recycling of PET. Most frequently, PET-waste is incinerated for energy recovery, used as additive in concrete composites or glycolysed to yield mixtures of monomers and undefined oligomers. While energetic and thermo-mechanical recycling entail downcycling of the material, chemical recycling requires considerable amounts of chemicals and demanding processing steps entailing toxic and ecological issues. This review provides a thorough survey of PET-recycling including energetic, material, thermo-mechanical and chemical methods. It focuses on chemical methods describing important reaction parameters and yields of obtained reaction products. While most methods yield monomers, only a few yield undefined low molecular weight oligomers for impaired applications (dispersants or plasticizers). Further, the present work presents an alternative chemical recycling method of PET in comparison to existing chemical methods.
The intelligent recycling of plastics waste is a major concern. Because of the widespread use of polyethylene terephtalate, considerable amounts of PET waste are generated that are ideally re-introduced into the material cycle by generating second generation products without loss of materials performance. Chemical recycling methods are often expensive and entail environmentally hazardous by-products. Established mechanical methods generally provide materials of reduced quality, leading to products of lower quality. These drawbacks can be avoided by the development of new recycling methods that provide materials of high quality in every step of the production cycle. In the present work, oligomeric ethylene terephthalate with defined degrees of polymerization and defined molecular weight is produced by melt-mixing PET with different quantities of adipic acid as an alternative pathway of recycling PET with respect to conventional methods, offering ecofriendly and economical aspects. Additionally, block-copolyesters of defined block length are designed from the oligomeric products.
Ethylene terephthalate and ethylene naphthalate oligomers of defined degree of polymerization were synthesized via chemical recycling of the parent polymers. The oligomers were used as defined building blocks for the preparation of novel block-co-polyesters having tailored sequence compositions. The sequence lengths were systematically varied using Design of Experiments. The dispersive surface energy and the specific desorption energy of the co-polymers were determined by inverse gas chromatography. The study shows that polyethylene terephthalate-polyethylene naphthalate (PET-PEN) block-co-polyesters of defined sequence lengths can be prepared. Furthermore, the specific and dispersive surface energies of the obtained block-co-polyesters showed a linear dependence on the oligomer molecular weight and it was possible to regulate and control their interfacial properties. In contrast, with the corresponding random-block-co-polyesters no such dependence was found. The synthesized block-co-polyesters could be used as polymeric modifying agents for stabilizing PET-PEN polymer blends.
The interfacial compatibility between polymers and nanoclay fillers as well as the thermostability of both components are important characteristics for processing them into polymer composites. While the polymer component is often grafted using common polymerization reactions, the nanoclay component is usually surface modified by surfactant treatment to improve compatibility. In the present study, the polymer ethylene vinyl alcohol and a nanoclay filler based on natural bentonite are both surface modified by different silanes, 3-glycidoxypropyltrimethoxysilane and methacryloxymethyltrimethoxysilane and their interfacial properties are investigated by inverse gas chromatography. The silane-modified samples had improved interfacial properties as reflected by a significant increase in dispersive and specific surface energies. Lewis acidities were determined using chloroform and 1,4-dioxane as polar probes and showed a good match between polymer and nanofiller interfaces. Lewis acidity was generally lower after silane-modification. Silanization yielded increased thermal stability of the treated samples. Thus, silanization led to improved compatibility and enhanced thermal stability which facilitates further processing.
Adapting characteristics of biomaterials specifically for in vitro and in vivo applications is becoming increasingly important in order to control interactions between material and biological systems. These complex interactions are influenced by surface properties like chemical composition, charge, mechanical and topographic attributes. In many cases it is not useful or even not possible to alter the base material but changing surface, to improve biocompatibility or to make surfaces bioactive, may be achieved by thin coatings. An already established method is the coating with polyelectrolyte multilayers (PEM). To adjust adhesion, proliferation and improve vitality of certain cell types, we modified the roughness of PEM coatings. We included different types nanoparticles (NP’s) in different concentrations into PEM coatings for controlling surface roughness. Surface properties were characterized and the reaction of 3 different cell types on these coatings was tested.
A new two-dimensional fluorescence sensor system was developed for in-line monitoring of mammalian cell cultures. Fluorescence spectroscopy allows for the detection and quantification of naturally occurring intra- and extracellular fluorophores in the cell broth. The fluorescence signals correlate the the cells' current redox state and other relevant process parameters. Cell culture pretests with twelve different excitation wavelengths showed that only three wavelengths account for a vast majority of spectral variation. Accordingly, the newly developed device utilizes three high-power LEDs as excitation sources in combination with a back-thinned CCD-spectrometer for fluorescence detection.
Continuous manufacturing is becoming more important in the biopharmaceutical industry. This processing strategy is favorable, as it is more efficient, flexible, and has the potential to produce higher and more consistent product quality. At the same time, it faces some challenges, especially in cell culture. As a steady state has to be maintained over a prolonged time, it is unavoidable to implement advanced process analytical technologies to control the relevant process parameters in a fast and precise manner. One such analytical technology is Raman spectroscopy, which has proven its advantages for process monitoring and control mostly in (fed-) batch cultivations. In this study, an in-line flow cell for Raman spectroscopy is included in the cell-free harvest stream of a perfusion process. Quantitative models for glucose and lactate were generated based on five cultivations originating from varying bioreactor scales. After successfully validating the glucose model (Root Mean Square Error of Prediction (RMSEP) of ∼0.2 g/L), it was employed for control of an external glucose feed in cultivation with a glucose-free perfusion medium. The generated model was successfully applied to perform process control at 4 g/L and 1.5 g/L glucose over several days, respectively, with variability of ±0.4 g/L. The results demonstrate the high potential of Raman spectroscopy for advanced process monitoring and control of a perfusion process with a bioreactor and scale-independent measurement method.
The physiology of vascular cells depends on stimulating mechanical forces caused by pulsatile flow. Thus, mechano-transduction processes and responses of primary human endothelial cells (ECs) and smooth muscle cells (SMCs) have been studied to reveal cell-type specific differences which may contribute to vascular tissue integrity. Here, we investigate the dynamic reorientation response of ECs and SMCs cultured on elastic membranes over a range of stretch frequencies from 0.01 to 1 Hz. ECs and SMCs show different cell shape adaptation responses (reorientation) dependent on the frequency. ECs reveal a specific threshold frequency (0.01 Hz) below which no responses is detectable while the threshold frequency for SMCs could not be determined and is speculated to be above 1 Hz. Interestingly, the reorganization of the actin cytoskeleton and focal adhesions system, as well as changes in the focal adhesion area, can be observed for both cell types and is dependent on the frequency. RhoA and Rac1 activities are increased for ECs but not for SMCs upon application of a uniaxial cyclic tensile strain. Analysis of membrane protrusions revealed that the spatial protrusion activity of ECs and SMCs is independent of the application of a uniaxial cyclic tensile strain of 1 Hz while the total number of protrusions is increased for ECs only. Our study indicates differences in the reorientation response and the reaction times of the two cell types in dependence of the stretching frequency, with matching data for actin cytoskeleton, focal adhesion realignment, RhoA/Rac1 activities, and membrane protrusion activity. These are promising results which may allow cell-type specific activation of vascular cells by frequency selective mechanical stretching. This specific activation of different vascular cell types might be helpful in improving strategies in regenerative medicine.
Poly(dimethylsiloxane) can be covalently coated with ultrathin NCO-sP(EO-stat-PO) hydrogel layers which permit covalent binding of cell adhesive moieties, while minimizing unspecific cell adhesion on non-functionalized areas. We applied long term uniaxial cyclic tensile strain (CTS) and revealed (a) the preservation of protein and cell-repellent properties of the NCO-sP(EO-stat-PO) coating and (b) the stability and bioactivity of a covalently bound fibronectin (FN) line pattern. We studied the adhesion of human dermal fibroblast (HDFs) on non-modified NCO-sP(EO-stat-PO) coatings and on the FN. HDFs adhered to FN and oriented their cell bodies and actin fibers along the FN lines independently of the direction of CTS. This mechanical long term stability of the bioactive, patterned surface allows unraveling biomechanical stimuli for cellular signaling and behavior to understand physiological and pathological cell phenomenon. Additionally, it allows for the application in wound healing assays, tissue engineering, and implant development demanding spatial control over specific cell adhesion.
The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies.
Plasma polymerization is used for the modification and control of surface properties of a highly transparent, thermoplastic elastomeric silicone copolymer, GENIOMER® 80 (G80). PEG-like diglyme plasma polymer films were deposited with ether retentions varying between 20% and 70% as measured by X-ray photoelectron spectroscopy analysis which did not affect the transparency of the substrate. Films with ether retentions of greater than 70% inhibit protein binding (bovine serum albumin and fibrinogen) and cell proliferation. A short oxygen plasma pretreatment enhances the adhesion and stability of the film as shown by protein binding and cell adhesion experiments. The transparency of the material and the stability of the coating makes this material a versatile bulk material for technical (e.g., lab-on-a-chip) and biomedical (e.g., intraocular lens) applications. The G80/plasma polymer composite is stable against vigorous washing and storage over 5 months and, therefore, offers an attractive alternative to poly(dimethylsiloxane).
Digital light microscopy techniques are among the most widely used methods in cell biology and medical research. Despite that, the automated classification of objects such as cells or specific parts of tissues in images is difficult. We present an approach to classify confluent cell layers in microscopy images by learned deep correlation features using deep neural networks. These deep correlation features are generated through the use of gram-based correlation features and are input to a neural network for learning the correlation between them. In this work we wanted to prove if a representation of cell data based on this is suitable for its classification as has been done for artworks with respect to their artistic period. The method generates images that contain recognizable characteristics of a specific cell type, for example, the average size and the ordered pattern.
Polyethylene glycol (PEG) is a widely used modification for drug delivery systems. It reduces undesired interaction with biological components, aggregation of complexes and serves as a hydrophilic linker of ligands for targeted drug delivery. However, PEGylation can also lead to undesired changes in physicochemical characteristics of chitosan/siRNA nanoplexes and hamper gene silencing.
To address this conflicting issue, PEG-chitosan copolymers were synthesized with stepwise increasing degrees of PEG substitution (1.5% to 8.0%). Subsequently formed PEG-chitosan/siRNA nanoplexes were characterized physicochemically and biologically. The results showed that small ratios of chitosan PEGylation did not affect nanoplex stability and density. However, higher PEGylation ratios reduced nanoplex size and charge, as well as cell uptake and final siRNA knockdown efficiency.
Therefore, we recommend fine-tuning of PEGylation ratios to generate PEG-chitosan/siRNA delivery systems with maximum bioactivity. The degree of PEGylation for chitosan/siRNA nanoplexes should be kept low in order to maintain optimal nanoplex efficiency.
Some widely used optical measurement systems require a scan in wavelength or in one spatial dimension to measure the topography in all three dimensions. Novel hyperspectral sensors based on an extended Bayer pattern have a high potential to solve this issue as they can measure three dimensions in a single shot. This paper presents a detailed examination of a hyperspectral sensor including a description of the measurement setup. The evaluated sensor (Ximea MQ022HG-IM-SM5X5-NIR) offers 25 channels based on Fabry–Pérot filters. The setup illuminates the sensor with discrete wavelengths under a specified angle of incidence. This allows characterization of the spatial and angular response of every channel of each macropixel of the tested sensor on the illumination. The results of the characterization form the basis for a spectral reconstruction of the signal, which is essential to obtain an accurate spectral image. It turned out that irregularities of the signal response for the individual filters are present across the whole sensor.
Hyperspectral imaging opens a wide field of applications. It is a well established technique in agriculture, medicine, mineralogy and many other fields. Most commercial hyperspectral sensors are able to record spectral information along one spatial dimension in a single acquisition. For the second spatial dimension a scan is required. Beside those systems there is a novel technique allowing to sense a two dimensional scene and its spectral information within one shot. This increases the speed of hyperspectral imaging, which is interesting for metrology tasks under rough environmental conditions. In this article we present a detailed characterization of such a snapshot sensor for later use in a snapshot full field chromatic confocal system. The sensor (Ximea MQ022HG-IM-SM5X5-NIR) is based on the so called snapshot mosaic technique, which offers 25 bands mapped to one so called macro pixel. The different bands are realized by a spatially repeating pattern of Fabry-Pèrot flters. Those filters are monolithically fabricated on the camera chip.