Cell Adhesion and Spreading on an Intrinsically Anti-Adhesive PEG Biomaterial - Biomaterials: Physics and Chemistry - page 410

topography is a more durable effect that dominates at longer time scales, suggesting its role
in the enabling of stable adhesion complexes, which is a process that occurs during more
than several hours. We consider that the topographic features may provide shelter to the
cells and prolong their residence time inside of the grooves. Added to this, the 'pulling' of
the cells on the weakly bound cell adhesion proteins may be less effective when they are
confined between the vertical walls than when the surface is smooth; as a consequence focal
adhesion contacts can develop into stable focal adhesion complexes.
Thus, the combination of different (bio)chemical, physical and mechanical properties of the
PEG hydrogels results in the observed cell adhesion on this intrinsically anti-adhesive
biomaterial. The effects are difficult to disentangle, and marked synergistic effects were
observed for example when using topographically patterned hydrogels that were incubated
with Vitronectin prior to cell culture.
As PEG is generally well known for its anti-adhesive properties and is widely applied in
biomedical applications, it is important to take into consideration what our study has
shown: physical and mechanical surface properties can impede the anti-adhesive
characteristics of PEG. On the other hand it also opens new opportunities for biomimetic
material design which does not rely on complicated and expensive biochemical surface
functionalization for manipulating cellular responses.
4. Acknowledgment
The author gratefully acknowledge funding from the Alexander von Humboldt Foundation
and the Federal Ministry for Education and Research (BMBF) in the form of a Sofja
Kovalevskaja Award (M. C. L.) and from the DFG Graduate School ''Biointerface'' (GRK
1035).
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