APPLICATION OF IN VIVO TISSUE ENGINEERED DECELLULARIZED CONNECTIVE TISSUE FOR CARDIOVASCULAR GRAFTS

We have developed in vivo tissue engineered autologous vascular grafts constructed in the subcutaneous of the recipient body. However, since the formation of the vascular grafts depends on the conditions of recipients including high risk or immature patients, immaturity in the fabricated tissues might be problematic for the severely diseased patients because of their suppressed regenerative activity. Therefore, possibility of the xenogeneic or the allogeneic implantation of the grafts should be evaluated. The objective of this study is to fabricate cardiovascular grafts using xenogeneic or allogeneic animals. Silicone rod molds were placed into subcutaneous pouches of beagle dogs, and after 4 weeks the implants with their surrounded connective tissues were harvested. Those were decellularized with detergents and stored at -20 °C for 1 week. Decellularized tubular connective tissues (internal diameter: 2 mm) were xeno-transplanted to abdominal aorta of the rats. Decellularized tubular connective tissues (internal diameter: 5 mm) were cut open and trimmed to elliptical sheets of 15 x 8 mm, they were allo-transplanted to carotid arteries of other beagle dogs as vascular patches. Both xenogeneic vascular grafts and allogeneic patch grafts performed well after transplantation, and the luminal surfaces after resection were very smooth. Histological evaluation also showed host cells infiltration into the grafts. Decellularized xenogeneic and allogeneic connective tissue membranes could be ideal vascular grafts.