TY - JOUR A1 - Appelhans, Marie-Luise A1 - Kampmann, Matthias A1 - Mottok, Jürgen A1 - Riederer, Michael A1 - Nagl, Klaus A1 - Steffens, Oliver A1 - Dünnweber, Jan A1 - Wildgruber, Markus A1 - Roth, Julius A1 - Stadler, Timo A1 - Palm, Christoph A1 - Weiß, Martin Georg A1 - Rochholz, Sandra A1 - Bierl, Rudolf A1 - Gschossmann, Andreas A1 - Haug, Sonja A1 - Schmidbauer, Simon A1 - Koch, Anna A1 - Westner, Markus A1 - Bary, Benedikt von A1 - Ellermeier, Andreas A1 - Vögele, Daniel A1 - Maiwald, Frederik A1 - Hierl, Stefan A1 - Schlamp, Matthias A1 - Ehrlich, Ingo A1 - Siegl, Marco A1 - Hüntelmann, Sven A1 - Wildfeuer, Matthias A1 - Brückl, Oliver A1 - Sterner, Michael A1 - Hofrichter, Andreas A1 - Eckert, Fabian A1 - Bauer, Franz A1 - Dawoud, Belal A1 - Rabl, Hans-Peter A1 - Gamisch, Bernd A1 - Schmidt, Ottfried A1 - Heberl, Michael A1 - Thema, Martin A1 - Mayer, Ulrike A1 - Eller, Johannes A1 - Sippenauer, Thomas A1 - Adelt, Christian A1 - Haslbeck, Matthias A1 - Vogl, Bettina A1 - Mauerer, Wolfgang A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Sax, Irmengard A1 - Gabor, Thomas A1 - Feld, Sebastian A1 - Linnhoff-Popien, Claudia A1 - Ławrowski, Robert Damian A1 - Langer, Christoph A1 - Schreiner, Rupert A1 - Sellmair, Josef ED - Baier, Wolfgang T1 - Forschung 2019 BT - Thema: Künstliche Intelligenz N2 - Bericht mit Forschungsprojekten aus verschiedenen Bereichen der OTH Regensburg mit dem Schwerpunktthema "Künstliche Intelligenz" und einem Gespräch zur "Medizin der Zukunft" T3 - Forschungsberichte der OTH Regensburg - 2019 KW - Forschung KW - Forschungsbericht KW - Künstliche Intelligenz Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7890 SN - 978-3-9818209-7-3 CY - Regensburg ER - TY - JOUR A1 - Lautenschläger, Toni A1 - Leis, Alexander A1 - Dendorfer, Sebastian A1 - Palm, Christoph A1 - Schreiner, Rupert A1 - Langer, Christoph A1 - Prommesberger, Christian A1 - Ławrowski, Robert Damian A1 - Dams, Florian A1 - Bornmann, Benjamin A1 - Navitski, Aliaksandr A1 - Serbun, Pavel A1 - Müller, Günter A1 - Liebetruth, Thomas A1 - Kohlert, Dieter A1 - Pernsteiner, Jochen A1 - Schreier, Franz A1 - Heerklotz, Sabrina A1 - Heerklotz, Allwin A1 - Boos, Alexander A1 - Herwald, Dominik A1 - Monkman, Gareth J. A1 - Treiber, Daniel A1 - Mayer, Matthias A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Johansen, Søren Peter A1 - Reichel, Marco A1 - Stoll, Andrea A1 - Briem, Ulrich A1 - Dullien, Silvia A1 - Renkawitz, Tobias A1 - Weber, Tim A1 - Dendorfer, Sebastian A1 - Grifka, Joachim A1 - Penzkofer, Rainer A1 - Barnsteiner, K. A1 - Jovanovik, M. A1 - Wernecke, P. A1 - Vögele, A. A1 - Bachmann, T. A1 - Plötz, Martin A1 - Schliekmann, Claus A1 - Wels, Harald A1 - Helmberger, Paul A1 - Kaspar, Marcel A1 - Hönicka, M. A1 - Schrammel, Siegfried A1 - Enser, Markus A1 - Schmidmeier, Monika A1 - Schroll-Decker, Irmgard A1 - Haug, Sonja A1 - Gelfert, Verena A1 - Vernim, Matthias ED - Baier, Wolfgang T1 - Forschungsbericht 2012 T3 - Forschungsberichte der OTH Regensburg - 2012 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-7834 CY - Regensburg ER - TY - JOUR A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Börner, Juliane A1 - Hörner, Eva A1 - Bentz, Alexander A1 - Salgado, Josefina A1 - Han, Hong A1 - Böse, Holger A1 - Probst, Jörn A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Schlunck, Günther T1 - Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata JF - PLoS ONE N2 - Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young’s modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of α-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (≈40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0076196 VL - 8 IS - 10 PB - PLOS ER - TY - JOUR A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Böse, Holger A1 - Schlunck, Günther A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Patterning of ultrasoft, agglutinative magnetorheological elastomers JF - Journal of applied polymer science N2 - A low-cost wax-cast molding technique for structuring ultrasoft (Young’s modulus ≤ 40 kPa), agglutinative magnetorheological elastomer (MRE) material is presented. MRE structures ranging from a few millimeters down to the micrometer range with highly reproducible results are possible. Semitransparent MREs are also fabricated and their surfaces modified accordingly. This method opens new possibilities for MREs in biomedical engineering and microfluidic applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 Y1 - 2013 U6 - https://doi.org/10.1002/app.38500 VL - 128 IS - 4 SP - 2508 EP - 2515 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Dillinger, Andrea Elisabeth A1 - Mayer, Matthias A1 - Schneider, Magdalena A1 - Weber, Gregor R. A1 - Goeppner, Corinna A1 - Tamm, Ernst R. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Fuchshofer, Rudolf T1 - Reactive changes in optic nerve astrocytes are mediated by CTGF, TGF beta 2 and increasing substratum stiffness JF - Investigative ophthalmology & visual science N2 - Purpose: Patients with primary open-angle glaucoma (POAG) show a stiffer peripapillary sclera, reactive astrocytes and a remodeled lamina cribrosa (LC). The changes are thought to be mediated by TGFβ2 and its downstream mediator CTGF. Recently we developed a murine glaucoma model by overexpressing CTGF in the anterior eye (βb1CTGF). In this study we investigated the glial lamina region of βb1CTGF mice, and the changes of astrocytes in response to CTGF and TGFβ2 as well as increasing substratum stiffness. Methods: Tangential sections of the glial LC of 2-month-old βb1CTGF mice and their wild-type littermates (WT) were stained with phalloidin and antibodies against GFAP, CTGF and fibronectin (FN). Murine optic nerve (ON) astrocytes from CD1 mice were isolated, cultured and characterized by GFAP staining. The astrocytes were treated with TGFβ2 (1ng/ml) and CTGF (50ng/ml and 100ng/ml). In addition, the cells were seeded on PDMS substrata with different stiffness (10, 30 and 60 kPa). Treated cells were analyzed by Western blotting, real-time RT-PCR and immunohistochemistry. Wound healing assays were performed to analyze migration rate following growth factor treatment. Results: βb1CTGF mice showed a massive increase in CTGF and GFAP in the glial LC when compared with WT mice. Moreover, an increase in FN staining and phalloidin-labeled actin was observed in the peripapillary sclera. Murine ON astrocytes reacted on increased substrate stiffness by increasing the synthesis of GFAP, vimentin and CTGF. Treatment of the cells with TGFβ2 and CTGF led to an enhanced migration rate. In addition, treatment resulted in an increased expression and synthesis of ECM proteins, including FN, tropoelastin, collagen type I and III. The in vitro findings correlated with those seen in the glaucoma mouse model. Conclusions: We conclude that changes in the ECM of LC and peripapillary sclera alter their biomechanical properties and thereby induce reactive changes in resident astrocytes. The reactive changes induced by higher stiffness of their surrounding ECM give rise to a self-amplifying process that includes increased TGFβ2/CTGF signaling and leads to synthesis of ECM and cytoskeletal proteins, a process that in turn augments the stiffness at the optic nerve head (ONH). Such a scenario may finally result in a vicious circle as the causative mechanism for ONH deformation in POAG. Y1 - 2015 VL - 56 IS - 7 PB - ASSOC RESEARCH VISION OPHTHALMOLOGY INC ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Gleixner, Ramona A1 - Mayer, Matthias A1 - Shamonin (Chamonine), Mikhail A1 - Schmauss, Bernhard T1 - Intensity referencing in an extrinsic optical fiber temperature sensor JF - Procedia Engineering N2 - Optical fiber sensors based on intensity measurement require some form of intensity referencing to avoid errors arising from parasitic losses. Known techniques of referencing such as balanced bridge, divided beam systems or two-wavelength referencing are not suitable for low-cost applications since they use relatively complicated optical components such as multiple LED sources, couplers, filters etc. In this work a novel method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of absorption edge in a semiconductor crystal is described. The sensor system comprises a single LED source and no optical fiber junctions. The emission spectrum of an LED depends on its temperature. The reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. The entire process is controlled by a microprocessor unit. Performance of a sensor system is investigated and it is shown that the losses in connectors may be compensated for. KW - Extrinsic optical fiber sensor KW - Intensity referencing KW - Temperature measurement KW - Absorption edge KW - Semiconductor KW - Hot-spot measurement Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.301 VL - 5 SP - 1095 EP - 1098 PB - Elsevier ER - TY - JOUR A1 - Stoll, Andrea A1 - Mayer, Matthias A1 - Monkman, Gareth J. A1 - Shamonin (Chamonine), Mikhail T1 - Evaluation of highly compliant magneto-active elastomers with colossal magnetorheological response JF - Journal of applied polymer science N2 - Highly compliant elastomers with a shear storage modulus as low as 25 Pa are prepared using commercially available silicone, plasticizer, and tactile mutator silicone additive. They are used as matrix material for magneto-active elastomers (MAEs) with carbonyl iron contents between 0 and 85 wt %. In the absence of an external magnetic field, the storage modulus of MAEs based on two selected mixtures ranges between ~100 Pa and ~2000 Pa. Addition of a mutator to the matrix mixture results in a long post-cure period depending on the curing temperature and the initial mixture. In the presence of a magnetic field, the presented MAEs exhibit a strong magneto-induced change in storage modulus resulting in a colossal magnetorheological effect of >106 % which is ~30 times higher than previously reported values. The results are of interest in applications using such elastomers as cell substrates with magnetically tunable rigidity. Y1 - 2014 U6 - https://doi.org/10.1002/app.39793 SN - 1097-4628 SN - 0021-8995 PB - Wiley CY - New York, NY ER - TY - CHAP A1 - Mayer, Matthias A1 - Monkman, Gareth J. T1 - Modern permanent magnetic materials: Advances and limits T2 - Inductica - Berlin Messe, 22-24 May 2007 Y1 - 2007 ER - TY - GEN A1 - Sorokin, Vladislav V. A1 - Stepanov, Gennady V. A1 - Vasiliev, V. G. A1 - Kramarenko, Elena Yu A1 - Mayer, Matthias A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Investigation of Dynamic Modulus and Normal Force of Magnetorheological Elastomers with Soft and Hard Magnetic Fillers T2 - NANO 2014, July 13 – 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials Y1 - 2014 CY - Moscow ER - TY - CHAP A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Surface Control Magneto-Active Polymers (MAP) T2 - EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers & artificial muscles, Pisa, 8-9 June N2 - Smart materials change their properties with external energy supply. Besides the known ferro-fluids and Magneto Rheological Fluid (MRF) also the Electro Active Polymer (EAP) and Magneto Rheological Elastomer (MRE) belong to these intelligent materials. The latest generation of magnetic elastomers represents a new class of composite materials. This consists of small magnetized particles which are sized in the micron or even nanometer range that in turn is bounded in a highly elastic rubber matrix. These materials are very often called MRE. Only recently, it has managed to develop these materials even further, so that very soft composite materials with a young?s modulus up to 10 kPa are possible. These soft polymers could be named magneto-active polymers. The combination of polymers with magnetic materials show novel and often enhanced properties. A precisely controllable young?s modulus and hardness, giant and non-homogeneous deformation behavior and rapid response to the magnetic field opens up new possibilities for various applications. Since MAP represent a very new technology, the behavior of these materials as a function of their composition and external conditions so far are not yet sufficiently understood. Therefore, some fundamental studies are necessary. In this paper, the mechanical surface properties are studied using a micro hardness meter. This work shows the possibility to control mechanical properties at the surface of MAP with new developed magnetic systems. Y1 - 2011 ER - TY - CHAP A1 - Mayer, Matthias A1 - Forster, Eva A1 - Rabindranath, Raman A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Highly compliant Magneto-Active Polymers (MAPs) T2 - Actuator'11, Bremen, May 2011 Y1 - 2011 ER - TY - CHAP A1 - Forster, Eva A1 - Rabindranath, Raman A1 - Mayer, Matthias A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Characterization of ultra soft Magneto-Active Polymers (MAPs) T2 - Conference proceedings / INDUCTICA 2011, Berlin, Germany, 24 - 26 May Y1 - 2011 ER - TY - RPRT A1 - Rabindranath, Raman A1 - Böse, Holger A1 - Probst, Jörn A1 - Schlunck, Günther A1 - Mayer, Matthias A1 - Forster, Eva A1 - Bentz, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - EAP mit magnetisch steuerbarer Elastizität zur Interaktion mit Bindegewebszellen MagElan BT - Teilvorhaben (HS-Regensburg) "Etablierung eines mechatronischen Systems zur (Magneto) Elastophorese von Bindegewebszellen" ; Schlussbericht ; Verbundprojekt "MagElan" ; Laufzeit des Vorhabens: 01.07.2009 - 30.10.2011 Y1 - 2012 N1 - Förderkennzeichen BMBF 13N10574 CY - Regensburg ER - TY - JOUR A1 - Dillinger, Andrea Elisabeth A1 - Weber, Gregor R. A1 - Mayer, Matthias A1 - Schneider, Magdalena A1 - Göppner, Corinna A1 - Ohlmann, Andreas A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Fuchshofer, Rudolf A1 - Keller, Kate A1 - Lozano, Diana C. A1 - Clark, Abbot T1 - CCN2/CTGF-A Modulator of the Optic Nerve Head Astrocyte JF - Frontiers in cell and developmental biology (Front Cell Dev Biol.) N2 - In primary open-angle glaucoma (POAG), a neurodegenerative disease of the optic nerve (ON) and leading cause of blindness, the optic nerve head (ONH) undergoes marked structural extracellular matrix (ECM) changes, which contribute to its permanent deformation and to degeneration of ON axons. The remodeling process of the ECM causes changes in the biomechanical properties of the ONH and the peripapillary sclera, which is accompanied by an increased reactivity of the resident astrocytes. The molecular factors involved in the remodeling process belong to the Transforming growth factor (TGF)-β superfamily, especially TGF-β2. In previous publications we showed that TGF-β2 induced ECM alterations are mediated by Cellular Communication Network Factor (CCN)2/Connective Tissue Growth Factor (CTGF) and recently we showed that CCN2/CTGF is expressed by astrocytes of the ON under normal conditions. In this study we wanted to get a better understanding of the function of CCN2/CTGF under normal and pathologic conditions. To this end, we analyzed the glial lamina and peripapillary sclera of CCN2/CTGF overexpressing mice and studied the effect of CCN2/CTGF and increasing substratum stiffness on murine ON astrocytes in vitro. We observed enhanced astrocyte reactivity in the ONH, increased ECM protein synthesis in the peripapillary sclera and increased Ccn2/Ctgf expression in the ONH during the pathologic development in situ. CCN2/CTGF treatment of primary murine ON astrocytes induced a higher migration rate, and increase of ECM proteins including fibronectin, elastin and collagen type III. Furthermore, the astrocytes responded to stiffer substratum with increased glial fibrillary acidic protein, vimentin, actin and CCN2/CTGF synthesis. Finally, we observed the reinforced appearance of CCN2/CTGF in the lamina cribrosa of glaucomatous patients. We conclude that reactive changes in ONH astrocytes, induced by the altered biomechanical characteristics of the region, give rise to a self-amplifying process that includes increased TGF-β2/CCN2/CTGF signaling and leads to the synthesis of ECM molecules and cytoskeleton proteins, a process that in turn augments the stiffness at the ONH. Such a scenario may finally result in a vicious circle in the pathogenesis of POAG. The transgenic CTGF-overexpressing mouse model might be an optimal model to study the chronic pathological POAG changes in the ONH. KW - astrocytes KW - extracellar matrix KW - glaucoma KW - glial lamina KW - growth factors KW - optic nerve KW - stiffness Y1 - 2022 U6 - https://doi.org/10.3389/fcell.2022.864433 VL - 10 PB - frontiers ER -