Fraunhofer Institute for Interfacial Engineering and Biotechnology

Stuttgart, Germany

Fraunhofer Institute for Interfacial Engineering and Biotechnology

Stuttgart, Germany

Time filter

Source Type

Oehr C.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
Vakuum in Forschung und Praxis | Year: 2017

Cost Structure of Plasma Processes — The share of investment costs and operating expense in vacuum coating processes. At a first glance coating costs of plasma processes seem to be dominated by high investments. Here it is shown that operating costs are at least of the same importance. Thus, it is reasonable to accept coating costs as only one contribution amongst others to the overall production costs. The example „solar cells”︁ shows that further enhancement of the coating process is less effective compared to an increase of energy conversion efficiency. On the other hand it appears more effective for cost reduction of hard coatings to decrease energy consumption and to increase the deposition rate instead of minimization of investment costs for the coating machine. The cost structures of depositions from the liquid phase and plasma processes are of the same order but growing environmental demands clearly favor the latter one (no liquid waste, etc.). The commonly used argument, that it is always preferable to run coating processes at atmospheric pressure without the use of (expensive) vacuum equipment rather than under vacuum conditions needs to be reconsidered particularly when noble gases are necessary at atmospheric pressure to obtain equal qualities of the coatings. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Jiang H.,Leibniz University of Hanover | Cao Z.,Leibniz University of Hanover | Schirrmeister S.,Uhde GmbH | Schiestel T.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Caro J.,Leibniz University of Hanover
Angewandte Chemie - International Edition | Year: 2010

chemical equation presentedBurns at both ends: By coupling water splitting and ethane dehydrogenation in a perovskite (BCFZ; BaCoxFe yZr1-x-yO3-δ) oxygen-permeable membrane reactor, hydrogen from water splitting was obtained on one side of the membrane, and ethylene was produced simultaneously on the other. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hijosa-Valsero M.,Institute Diagnostico Ambiental y Estudios del Agua IDAEA | Molina R.,CSIC - Institute of Advanced Chemistry of Catalonia | Schikora H.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Muller M.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Bayona J.M.,Institute Diagnostico Ambiental y Estudios del Agua IDAEA
Water Research | Year: 2013

Two different nonthermal plasma reactors at atmospheric pressure were assessed for the first time for cyanide removal (1 mg L-1) from aqueous solutions (0.025 M NaHCO3/NaOH buffer, pH 11) at laboratory scale. Both devices were dielectric barrier discharge (DBD) reactors; one of them was a conventional batch reactor (R1) and the other one was a coaxial thin falling water film reactor (R2). A first-order degradation kinetics was proposed for both experiments, obtaining kR1 = 0.5553 min-1 and kR2 = 0.7482 min-1. The coaxial reactor R2 yielded a removal of 99% within only 3 min. Energy efficiencies (G) were calculated, yielding 1.74 mg kW-1 h-1 for R1 and 127.9 mg kW-1 h-1 for R2. When the treatment was applied to industrial wastewaters, cyanide elimination was confirmed, although at a lower rate (above 92% removal in 90 min with R2). Therefore, plasma reactors could be a relevant alternative to established advanced oxidation techniques (UV, H2O2, ozonation, etc.) for the removal of cyanide from wastewaters with low organic loads or even drinking waters. © 2013 Elsevier Ltd.

Surmenev R.A.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Surmeneva M.A.,Tomsk Polytechnic University | Ivanova A.A.,Tomsk Polytechnic University
Acta Biomaterialia | Year: 2014

A systematic analysis of results available from in vitro, in vivo and clinical trials on the effects of biocompatible calcium phosphate (CaP) coatings is presented. An overview of the most frequently used methods to prepare CaP-based coatings was conducted. Dense, homogeneous, highly adherent and biocompatible CaP or hybrid organic/inorganic CaP coatings with tailored properties can be deposited. It has been demonstrated that CaP coatings have a significant effect on the bone regeneration process. In vitro experiments using different cells (e.g. SaOS-2, human mesenchymal stem cells and osteoblast-like cells) have revealed that CaP coatings enhance cellular adhesion, proliferation and differentiation to promote bone regeneration. However, in vivo, the exact mechanism of osteogenesis in response to CaP coatings is unclear; indeed, there are conflicting reports of the effectiveness of CaP coatings, with results ranging from highly effective to no significant or even negative effects. This review therefore highlights progress in CaP coatings for orthopaedic implants and discusses the future research and use of these devices. Currently, an exciting area of research is in bioactive hybrid composite CaP-based coatings containing both inorganic (CaP coating) and organic (collagen, bone morphogenetic proteins, arginylglycylaspartic acid etc.) components with the aim of promoting tissue ingrowth and vascularization. Further investigations are necessary to reveal the relative influences of implant design, surgical procedure, and coating characteristics (thickness, structure, topography, porosity, wettability etc.) on the long-term clinical effects of hybrid CaP coatings. In addition to commercially available plasma spraying, other effective routes for the fabrication of hybrid CaP coatings for clinical use still need to be determined and current progress is discussed. © 2013 Acta Materialia Inc.

Lemuth K.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Steuer K.,University of Stuttgart | Albermann C.,University of Stuttgart
Microbial Cell Factories | Year: 2011

Background: The xanthophyll astaxanthin is a high-value compound with applications in the nutraceutical, cosmetic, food, and animal feed industries. Besides chemical synthesis and extraction from naturally producing organisms like Haematococcus pluvialis, heterologous biosynthesis in non-carotenogenic microorganisms like Escherichia coli, is a promising alternative for sustainable production of natural astaxanthin. Recent achievements in the metabolic engineering of E. coli strains have led to a significant increase in the productivity of carotenoids like lycopene or β-carotene by increasing the metabolic flux towards the isoprenoid precursors. For the heterologous biosynthesis of astaxanthin in E. coli, however, the conversion of β-carotene to astaxanthin is obviously the most critical step towards an efficient biosynthesis of astaxanthin.Results: Here we report the construction of the first plasmid-free E. coli strain that produces astaxanthin as the sole carotenoid compound with a yield of 1.4 mg/g cdw (E. coli BW-ASTA). This engineered E. coli strain harbors xanthophyll biosynthetic genes from Pantoea ananatis and Nostoc punctiforme as individual expression cassettes on the chromosome and is based on a β-carotene-producing strain (E. coli BW-CARO) recently developed in our lab. E. coli BW-CARO has an enhanced biosynthesis of the isoprenoid precursor isopentenyl diphosphate (IPP) and produces β-carotene in a concentration of 6.2 mg/g cdw. The expression of crtEBIY along with the β-carotene-ketolase gene crtW148 (NpF4798) and the β-carotene-hydroxylase gene (crtZ) under controlled expression conditions in E. coli BW-ASTA directed the pathway exclusively towards the desired product astaxanthin (1.4 mg/g cdw).Conclusions: By using the λ-Red recombineering technique, genes encoding for the astaxanthin biosynthesis pathway were stably integrated into the chromosome of E. coli. The expression levels of chromosomal integrated recombinant biosynthetic genes were varied and adjusted to improve the ratios of carotenoids produced by this E. coli strain. The strategy presented, which combines chromosomal integration of biosynthetic genes with the possibility of adjusting expression by using different promoters, might be useful as a general approach for the construction of stable heterologous production strains synthesizing natural products. This is the case especially for heterologous pathways where excessive protein overexpression is a hindrance. © 2011 Lemuth et al; licensee BioMed Central Ltd.

Hoch E.,University of Stuttgart | Tovar G.E.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Borchers K.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery | Year: 2014

Free-form fabrication techniques, often referred to as '3D printing', are currently tested with regard to the processing of biological and biocompatible materials in general and for fabrication of vessel-like structures in particular. Such computer-controlled methods assemble 3D objects by layer-wise deposition or layer-wise cross-linking of materials. They use, for example, nozzle-based deposition of hydrogels and cells, drop-on-demand inkjet-printing of cell suspensions with subsequent cross-linking, layer-by-layer cross-linking of synthetic or biological polymers by selective irradiation with light and even laser-induced deposition of single cells. The need of vessel-like structures has become increasingly crucial for the supply of encapsulated cells for 3D tissue engineering, or even with regard to future application such as vascular grafts. The anticipated potential of providing tubes with tailored branching geometries made of biocompatible or biological materials pushes future visions of patient-specific vascularized tissue substitutions, tissue-engineered blood vessels and bio-based vascular grafts. We review here the early attempts of bringing together innovative free-form manufacturing processes with bio-based and biodegradable materials. The presented studies provide many important proofs of concepts such as the possibility to integrate viable cells into computer-controlled processes and the feasibility of supplying cells in a hydrogel matrix by generation of a network of perfused channels. Several impressive results in the generation of complex shapes and high-aspect-ratio tubular structures demonstrate the potential of additive assembly methods. Yet, it also becomes obvious that there remain major challenges to simultaneously match all material requirements in terms of biological functions (cell function supporting properties), physicochemical functions (mechanical properties of the printed material) and process-related (viscosity, cross-linkability) functions, towards the demanding goal of biofabricating artificial blood vessels. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Surmeneva M.A.,Tomsk Polytechnic University | Surmenev R.A.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
Vacuum | Year: 2015

The present study reports the fabrication of a nano-hydroxyapatite (HA) film on an AZ31 magnesium alloy via radio frequency (RF) magnetron sputtering. The phase composition, microstructure, and surface morphology of the HA coatings were investigated using X-ray diffraction and atomic force microscopy. The polarization tests in a 3.5 wt.% NaCl solution were performed to examine the corrosion behaviour of the HA-coated magnesium alloy. Two HA coating thicknesses of 700 nm and 1500 nm were studied. The coatings homogeneously covered the entire surface of the substrates. In the case of a greater coating thickness, larger crystallites were formed. The potentiodynamic polarization test demonstrated that a 1500-nm thick nanocrystalline HA coating significantly improved the corrosion resistance of the bare AZ31 magnesium alloy. © 2015 Elsevier Ltd.

Purschke F.G.,University of Stuttgart | Hiller E.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Trick I.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Rupp S.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
Molecular and Cellular Proteomics | Year: 2012

The majority of microorganisms persist in nature as surface-attached communities often surrounded by an extracellular matrix, called biofilms. Most natural biofilms are not formed by a single species but by multiple species. Microorganisms not only cooperate as in some multispecies biofilms but also compete for available nutrients. The Gram-negative bacterium Pseudomonas aeruginosa and the polymorphic fungus Candida albicans are two opportunistic pathogens that are often found coexisting in a human host. Several models of mixed biofilms have been reported for these organisms showing antagonistic behavior. To investigate the interaction of P. aeruginosa and C. albicans in more detail, we analyzed the secretome of single and mixed biofilms of both organisms using MALDI-TOF MS/MS at several time points. Overall 247 individual proteins were identified, 170 originated from P. aeruginosa and 77 from C. albicans. Only 39 of the 131 in mixed biofilms identified proteins were assigned to the fungus whereby the remaining 92 proteins belonged to P. aeruginosa. In single-species biofilms, both organisms showed a higher diversity of proteins with 73 being assigned to C. albicans and 154 to P. aeruginosa. Most interestingly, P. aeruginosa in the presence of C. albicans secreted 16 proteins in significantly higher amounts or exclusively among other virulence factors such as exotoxin A and iron acquisition systems. In addition, the high affinity iron-binding siderophore pyoverdine was identified in mixed biofilms but not in bacterial biofilms, indicating that P. aeruginosa increases its capability to sequester iron in competition with C. albicans. In contrast, C. albicans metabolism was significantly reduced, including a reduction in detectable iron acquisition proteins. The results obtained in this study show that microorganisms not only compete with the host for essential nutrients but also strongly with the present microflora in order to gain a competitive advantage. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc.

Muller M.,Fraunhofer Institute for Interfacial Engineering and Biotechnology | Oehr C.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
Plasma Processes and Polymers | Year: 2011

The potential of contact angle measurements (CAM) as an analytical tool to characterize surface treatments or modifications is often not fully exploited. Agreeing with Strobel and Lyons, comparing contact angles is often much more reasonable than comparing deduced data like surface energies, because the latter are based on models, in turn involving the influence and knowledge of intermolecular forces at the respective interfaces. For a comprehensive picture, the measurement of contact angles itself has to be considered together with the appropriate model and the available techniques to carry out CAM. An appropriate measurement procedure will be given and a brief discussion of some models to derive free surface energy from CAM. The information that could be derived from contact angle measurements is very useful to characterize the outermost layer of a surface until it is carried out carefully. To compare the results with other working groups it is essential to describe the measurement procedure properly. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rupp S.,Fraunhofer Institute for Interfacial Engineering and Biotechnology
Engineering in Life Sciences | Year: 2013

Within the last decade, biotechnology gained pace in substituting petro-based products for the chemical industries. This is visible with the appearance of bio-based products in the market, from biosurfactants to bio-based polymers like polylactic acid to bio-ethylene. These technologies are mainly based on established fermentation technologies fostered by the use of renewable resources, culminating in the establishment of biorefineries that may be connected directly to the existing chemical infrastructure. Besides these large-scale technologies, the combination of molecular technologies, microfluidic devices, and enzymatic and cell-free conversions are currently developed to create new bioproduction systems enabling the production of compounds that may not be produced within a cell. This article summarizes some of the current ideas that are currently in development paving the way for a next generation of biotechnology. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Loading Fraunhofer Institute for Interfacial Engineering and Biotechnology collaborators
Loading Fraunhofer Institute for Interfacial Engineering and Biotechnology collaborators