The behavior of MC3T3-E1 cells on chitosan/poly-L-lysine composite films: Effect of nanotopography, surface chemistry, and wettability

In the present work, a series of composite films were produced from chitosan/poly-L-lysine blend solutions. The Surface topography, chemistry, and wettability of composite films were characterized by atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle assay, respectively. For all composite films, blending with poly-L-lysine induced changes in surface chemistry and wettability. Interestingly, it was also found that increasing poly-L-lysine weighs fraction in blend solutions could result in different nanoscaled surface topographic features, which displayed particle-, granule-, or fiber-dominant morphologies. MC3T3-E1 osteoblast-like cells were Cultured on all composite films to evaluate the effects of surface nanotopography, chemistry, and wettability on cell behavior. The observations indicate; that MC3T3-E1 cell behavior was affected by surface topography, chemistry, and wettability simultaneously and that cells showed strong responses to surface topography. On fiber-dominant surface, cells fully spread with obvious cytoskeleton organization and exhibited significantly higher level of adhesion and proliferation compared with particle- or granule-dominant surfaces. Furthermore, fiber-dominant Surface also induced greater expression of mature osteogenic marker osteocalcin and higher mineralization based on RT-PCR and von Kossa staining. The results Suggest that topographic modification of chitosan substratum at the nanoscale may be exploited in regulating cell behavior for its applications in tissue engineering. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 453-465,2009