Proliferation of mesenchymal stem cell on chitosan films associated with convex micro-topography

Topographical micro-structures of material surfaces are known to influence cell behavior. In this study, alignment and proliferation of mesenchymal stem cells (MSCs) on chitosan (CS) films with different microtopography was investigated. A modified solvent-non-solvent method was used to produce micro-well polystyrene films which were used as templates for preparation of micro-hilled CS films. The alignment and proliferation of MSCs on CS films were characterized by scanning electron microscopy and the MTT assay, respectively. Polystyrene films with different micro-well diameters were produced under different conditions. We successfully produced CS films with micro-hills of 10 μm (CS10) and 5-30 μm (CS5-30) by a molding approach. MSCs cultured on CS10 covered the tightly packed micro-hills and flattened polygonally. In contrast, MSCs on CS5-30 mostly adhered between loosely packed micro-hills and demonstrated elongated extensions. The proliferation rate of MSCs on CS5-30 was highest on day 4 (66% on CS5-30 versus 46% on CS10 and 24% on smooth CS) and day 8 (106% on CS5-30 versus 38% on CS10 and 72% on smooth CS). It is reasonable to suggest that spatially and dimensionally dispersed micro-hills on CS films facilitate the alignment and proliferation of MSCs. This may be used to physically modify CS for tissue-engineering applications.