Regenerative medicine of the gastrointestinal tract.

Regenerative biology/tissue engineering offers potential solutions for the repair and augmentation of diseased tissues and organs. Tissue engineering technology platforms currently under development for organ regeneration may function in part by recapitulating key mechanistic and signaling pathways associated with embryonic organogenesis. Temporal observations of observed morphological outcomes from the regeneration of tubular organs provide insights into the mechanisms of action associated with the activation of regenerative pathways in preclinical animal models and humans. These include induction of a neo-blastema, regeneration of laminarily organized mural elements (i.e., lamina propria, sub-mucosa, and muscularis), and formation of context appropriate transitional junctions at the point of anastomosis with other tissue elements. These results provide the foundation for a regenerative technology applicable to hollow organs of the gastrointestinal (GI) tract including esophagus and small intestine. Factors affecting the efficacy of observed regenerative outcomes within the GI tract include the roles of vascularization, innervations, and mesenchymal signaling. These will be discussed in the context of an overall mechanism of adult regeneration potentially applicable by the tissue engineering and regenerative medicine industry for continued development of hollow neo-organ products.