Effect of Implantation Site on Hepatocytes Heterotopically Transplanted on Biodegradable Polymer Scaffolds

We investigated the engraftment of heterotopically transplanted hepatocytes in three sites: the subcutaneous space, the small intestinal mesentery, and the omentum to determine the optimal location for tissue-engineered liver constructs. Hepatocytes were isolated from inbred Lewis rats and placed on polymer constructs. Cell-polymer constructs were implanted into the subcutaneous space of the abdominal wall, the small intestinal mesentery, and the omentum of Lewis rats. One group of rats had undergone previous portacaval shunt. Animals were killed 2 or 4 weeks after implantation and the constructs were analyzed for engraftment, using computer-assisted morphometric analysis. Engraftment was greatest in the omentum with less engraftment in the mesentery. There was minimal engraftment in the subcutaneous space in all specimens. Prior portacaval shunt increased engraftment in the mesentery and the omentum, but not the subcutaneous space. The omentum is the most favorable bed for engraftment of hepatocyte-polymer tissue-engineered constructs and the addition of a portacaval shunt increases survival of transplanted hepatocytes in the omentum and mesentery.