Tissue-engineered large intestine resembles native colon with appropriate in vitro physiology and architecture

Objective: Novel production and in vitro characterization of tissue engineered colon. Summary Background Data: The colon provides important functions of short chain fatty acid production, sodium and water absorption, and storage. We report the first instance of tissue-engineered colon (TEC) production from autologous cells and its in vitro characterization. Methods: Organoid units, mesenchymal cell cores surrounded by a polarized epithelia derived from full thickness sigmoid colon dissection from neonatal Lewis rats, adult rats, and tissue engineered colon itself, were implanted on a polymer scaffold into the omentum of syngeneic hosts. TEC was either anastomosed at 4 weeks or excised for Ussing chamber studies or histology, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay. Results: TEC was generated by 100% of all animals without regard to tissue source, the first instance of engineered intestine from adult cells or an engineered tissue. TEC architecture is identical to native with muscularis propria staining for actin, acetylcholinesterase detected in a linear distribution in the lamina propria, S100-positive cells, ganglion cells, and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay similar to native colon. Ussing chamber data indicated in vitro function consistent with mature colonocytes, and a positive short circuit current response to theophylline indicating intact ion transfer. TEM showed normal microarchitecture. Colon architecture was maintained in anastomosis with gross visualization of fluid uptake. Conclusions: TEC can be successfully produced with fidelity to native architecture and in vitro function from neonatal syngeneic tissue, adult tissue, and TEC itself.