Mesenchymal stem cell differentiation driven by osteoinductive bioactive nanoscale topographies

Abstract

Human mesenchymal stem cells (hMSCs) respond to the characteristics of their surrounding microenvironment, i.e., their extracellular matrix (ECM). The possibility of mimicking the ECM offers the opportunity to elicit specific cell behaviors. The control of surface properties of a biomaterial at the scale level of the components of the ECM has the potential to effectively modulate cell response. Ordered nanoscale silicon pillar arrays were fabricated using reverse micelles of block copolymers on full wafers, with standard deviations lower than 15%. Bioactive synthetic peptides were covalently grafted on nanoarrays to evaluate possible synergies between chemistry and topography on osteogenic differentiation of hMSCs. Functionalization with RGD (Arg-Gly-Asp) and BMP-2 (bone morphogenetic protein-2) mimetic peptides lead to an enhancement of osteogenic differentiation. Bare nanopillar arrays of reduced pitch were found to promote faster hMSC differentiation. These findings highlight the relevance of investigating possibilities of engineering in vitro systems which can be fine-tuned according to the envisaged cell response.