Pendant small functional groups on poly(ϵ-caprolactone) substrate modulate adhesion, proliferation and differentiation of human mesenchymal stem cells.

Probing stem cell-biomaterial interactions is of great significance in both gaining profound understanding of stem cell biology and advancing tissue regeneration. In the present work, we developed a series of poly(ϵ-caprolactone) (PCL) films bearing distinct pendant small functional groups to study the effects of biomaterial substrate chemistry on stem cell behaviors. PCL films, bearing hydroxyl (OH), methyl (CH₃), carboxyl (COOH) and amino (NH₂), demonstrated varied surface properties, such as wettability, serum protein adsorption and surface topographical feature. In comparison with pristine PCL film, the adhesion of hMSCs on PCL-COOH, PCL-OH and PCLCO films was significantly promoted and cells slightly outgrew on PCL-NH₂ and PCL-COOH films. Most importantly, the tri-lineage differentiation of hMSCs varied on this series of PCL films, with the best osteogenesis achieved on PCL-NH₂ film, PCL and PCL-CH₃ films supporting the superior adipogenic differentiation and PCL-CH₃ film being the most favorable one for chondrogenesis. This study highlights the critical roles of surface chemistry in modulating the fates of MSCs and potentially provides a practical guidance in developing instructive tissue engineering scaffolds.