Badylak SF.

Regenerative medicine can be defined as efforts to change the default mechanism of mammalian wound healing from one of inflammation and scarring to regeneration of injured or missing tissues. Such a therapeutic approach represents a dramatic paradigm shift in the practice of medicine. What factors facilitate the development of effective regenerative medicine strategies?

Regenerative medicine is typically based upon the strategic use of undifferentiated stem and progenitor cells, inductive bioscaffolds, and appropriate micro-environmental cues that signal the need for tissue reconstruction. In many respects, the desired result is the recapitulation of developmental biology but limited to a specific tissue or organ. There are many fundamental questions yet to be answered with regard to implementation of such strategies in an aging population. Do aging cells have the same potential for regeneration as young cells? Are biologic scaffolds composed of extracellular matrix from fetal tissues more "instructive" than biologic scaffolds harvested from adult extracellular matrix? How does the micro-environment of aged tissues and organs differ from that or neonatal tissues and organs? These and other questions will be discussed.