Targeting the stem cell niche with regenerative biomaterials

Regenerative medicine aims to restore form and function to aged, injured, and diseased tissues. One strategy that is gaining traction is in vivo regenerative medicine. Many adult tissues possess stem and progenitor cells that are enlisted to repair minor tissue damage after insult. However, in the setting of disease, aging, or criticalsized injuries, the microenvironment may lack structural elements, physical, and/or chemical cues required to drive repair to completion. Natural and synthetic materials offer an opportunity to facilitate the repair process by restoring the natural reparative capacity of adult tissues. Using design criteria selected based upon an understanding of the inductive niche cues that naturally instruct stem and progenitor cell behavior and fate, it is possible to elicit tissue repair by implementing a cell-free approach. This review highlights recent studies that assess biomaterials for in vivo regenerative medicine applications and demonstrate a capacity for controlling stem and progenitor cell behavior to restore tissue form and function.