An in vivo study of a gold nanocomposite biomaterial for vascular repair.

Currently vascular repairs are treated using synthetic or biologic patches, however these patches have an array of complications, including calcification, rupture, re-stenosis, and intimal hyperplasia. An active patch material composed of decellularized tissue conjugated to gold nanoparticles (AuNPs) was developed and the long term biocompatibility and cellular integration was investigated. Porcine abdominal aortic tissue was decellularized and conjugated with 100 nm gold nanoparticles (AuNP). These patches were placed over a longitudinal arteriotomy of the thoracic aorta in six pigs. The animals were monitored for six months. Gross, histological, and immunohistochemical analyses of the patches were performed after euthanasia. Grossly there was minimal scar tissue with the patches still visible on the outer surface of the vessel. The inner lumen was smooth with a seamless transition from patch to native tissue. Histology demonstrated infiltration of host cells into the patch material. The immunohistochemical results demonstrated an endothelial cell layer forming over the patch within the vessel. Smooth muscle cells were repopulating the biomaterial in all animals. These results demonstrated that the AuNP biomaterial patch integrated well with the host tissue and did not failed over the six month implantation time.