Insights into the role of material surface topography and wettability on cell-material interactions

This work investigates the effect of surface topography and biomaterial wettability on protein absorption, cell attachment, proliferation and morphology and reveals important insights in the complexity of cell-material interactions. We use various materials, i.e. poly(dimethyl siloxane) (PDMS), poly(L-lactic acid) (PLLA), a co-polymer of poly(ethylene oxide) and poly(butylene terephtalate) (PEOT/PBT) and tissue culture polystyrene (TCPS) as a reference. These materials are used extensively in biomedical applications and tissue engineering and have differences in hydrophobicity. Patterning of PDMS, PLLA and PEOT/PBT with a micropattern array of pillars with variable pillar spacing and pillar height induces changes in the wettability of their surfaces without changes in their surface chemistry. The cell study is performed using C2C12 pre-myoblasts cells. Our results reveal a clear effect of surface topography, and to a lesser extent of material hydrophobicity, on cell attachment, morphology and proliferation. Generally, surface topography on high hydrophobicity materials improves initial C2C12 cell attachment, whereas less hydrophobic and nonpatterned materials seem to support higher cell proliferation and spreading. With respect to cell morphology, surface topography seems dominant over material wettability; although the transition where cells change from growing on top of the pillars to growing on the underlying surface appears to be determined by the material wettability. These findings are important in the design of biomaterials in various applications including implants, bio-artificial organs and tissue engineering