Alimentary Tract

Publisher Summary This chapter discusses the current knowledge regarding tissue engineering of different components of the alimentary tract, highlighting successful strategies and some of the obstacles in this rapidly developing field that need to be addressed to ensure success in this field. Scaffold materials derived from small intestinal submucosa (SIS) are investigated most widely to tissue engineer replacement esophageal tissue. SIS consists of extracellular matrix material harvested from porcine small intestine and are used extensively in tissue-engineering experiments. The transplantation of organoid units onto biodegradable polymer scaffolds followed by implantation into the omentum of syngeneic adult animals results in the formation of neointestinal cysts attached to a vascular pedicle with mucosa facing a lumen that contains mucoid material. The mucosa of the neointestine created with this technique shows morphological similarities to native intestine, including the formation of a primitive crypt-villus axis lined with columnar epithelial cells and goblet cells, and a polarized epithelium with brush border enzyme sucrase expressed at the apical surface and laminin at the basolateral surface. Rapid vascular in-growth into the tissue-engineered intestine is essential to maintain the viability and engraftment of cells seeded on the scaffold. The tissue-engineered intestine exhibits lower levels of bFGFG and VEGF and a fixed capillary density compared with native juvenile bowel. Preservation of the vascular structure in decellularized porcine small bowel is used to engineer tissue with an innate vascularization.