Chemical control of FGF-2 release for promoting calvarial healing with adipose stem cells.

Chemical control of protein secretion using a small molecule approach provides a powerful tool to optimize tissue engineering strategies by regulating the spatial and temporal dimensions that are exposed to a specific protein. We placed fibroblast growth factor 2 (FGF-2) under conditional control of a small molecule and demonstrated greater than 50-fold regulation of FGF-2 release as well as tunability, reversibility, and functionality in vitro. We then applied conditional control of FGF-2 secretion to a cell-based, skeletal tissue engineering construct consisting of adipose stem cells (ASCs) on a biomimetic scaffold to promote bone formation in a murine critical-sized calvarial defect model. ASCs are an easily harvested and abundant source of postnatal multipotent cells and have previously been demonstrated to regenerate bone in critical-sized defects. These results suggest that chemically controlled FGF-2 secretion can significantly increase bone formation by ASCs in vivo. This study represents a novel approach toward refining protein delivery for tissue engineering applications.