5.19 In Vivo Bioreactors

The term bioreactor describes a device or system that supports a biologically active environment and has been used to optimize in vitro cell culture conditions for tissue engineering applications. On the contrary, the relatively new concept of an “in vivo bioreactor” aims to maximize the role of the patient’s body in the regeneration of tissues and organs by supplying progenitor or stem cells, growth factors, and cytokines that exert specific effects on these cells, a scaffold that may replace or support form or function of impaired tissues or organs, and the extracellular environment for protection and nutrition, thereby eliminating the need for external supply of cells, growth factors, and scaffolds.