@article{KastenNaserBruellhoffetal.2014, author = {Kasten, Annika and Naser, Tamara and Br{\"u}llhoff, Kristina and Fiedler, J{\"o}rg and M{\"u}ller, Petra and M{\"o}ller, Martin and Rychly, Joachim and Groll, J{\"u}rgen and Brenner, Rolf E.}, title = {Guidance of Mesenchymal Stem Cells on Fibronectin Structured Hydrogel Films}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {10}, doi = {10.1371/journal.pone.0109411}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114897}, pages = {e109411}, year = {2014}, abstract = {Designing of implant surfaces using a suitable ligand for cell adhesion to stimulate specific biological responses of stem cells will boost the application of regenerative implants. For example, materials that facilitate rapid and guided migration of stem cells would promote tissue regeneration. When seeded on fibronectin (FN) that was homogeneously immmobilized to NCO-sP(EO-stat-PO), which otherwise prevents protein binding and cell adhesion, human mesenchymal stem cells (MSC) revealed a faster migration, increased spreading and a more rapid organization of different cellular components for cell adhesion on fibronectin than on a glass surface. To further explore, how a structural organization of FN controls the behavior of MSC, adhesive lines of FN with varying width between 10 mu m and 80 mu m and spacings between 5 mu m and 20 mu m that did not allow cell adhesion were generated. In dependance on both line width and gaps, cells formed adjacent cell contacts, were individually organized in lines, or bridged the lines. With decreasing sizes of FN lines, speed and directionality of cell migration increased, which correlated with organization of the actin cytoskeleton, size and shape of the nuclei as well as of focal adhesions. Together, defined FN lines and gaps enabled a fine tuning of the structural organization of cellular components and migration. Microstructured adhesive substrates can mimic the extracellular matrix in vivo and stimulate cellular mechanisms which play a role in tissue regeneration.}, language = {en} } @article{MayerRabindranathBoerneretal.2013, author = {Mayer, Matthias and Rabindranath, Raman and B{\"o}rner, Juliane and H{\"o}rner, Eva and Bentz, Alexander and Salgado, Josefina and Han, Hong and B{\"o}se, Holger and Probst, J{\"o}rn and Shamonin, Mikhail and Monkman, Gereth J. and Schlunck, G{\"u}nther}, title = {Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata}, series = {PLOS ONE}, volume = {8}, journal = {PLOS ONE}, number = {10}, issn = {1932-6203}, doi = {10.1371/journal.pone.0076196}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128246}, pages = {e76196}, year = {2013}, abstract = {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 alpha-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (approximate to 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.}, language = {en} }