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, Mikhail
A1  - Monkman, Gereth 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 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.
KW  - elastic magnetic-materials
KW  - smooth muscle actin
KW  - magnetorheological elastomers
KW  - adhesion
KW  - mechanotransduction
KW  - stiffness
KW  - tension
KW  - mechanics
KW  - hydrogels
KW  - behavior
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128246
SN  - 1932-6203
VL  - 8
IS  - 10
ER  - 
TY  - JOUR
A1  - Kasten, Annika
A1  - Naser, Tamara
A1  - Brüllhoff, Kristina
A1  - Fiedler, Jörg
A1  - Müller, Petra
A1  - Möller, Martin
A1  - Rychly, Joachim
A1  - Groll, Jürgen
A1  - Brenner, Rolf E.
T1  - Guidance of Mesenchymal Stem Cells on Fibronectin Structured Hydrogel Films
JF  - PLOS ONE
N2  - 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.
KW  - adhesion dynamics
KW  - migration
KW  - coatings
KW  - force
KW  - networks
KW  - traction
KW  - stress
KW  - tension
KW  - focal adhesions
KW  - tissue morphogenesis
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114897
VL  - 9
IS  - 10
ER  -