Bioreactor design for in vitro endothelialization of small diameter vascular grafts made of porcine intestinal submucosa (SIS)

The lack of success of small diameter vascular grafts $( <6$ mm) has driven biomedical engineers to develop multiple strategies for their improvement. One of the most promising proposals involves the formation of a healthy and uniform endothelial layer. The early formation of this tissue on the lumen of the graft prevents thrombosis and excessive proliferation of smooth muscle cells, which can lead to intimal hyperplasia. Based on this theory, the Biomedical Engineering Group at Universidad de los Andes (GIB) is currently working to develop a smalldiameter vascular graft made of porcine intestinal submucosa (SIS) capable of promoting endothelial cell adhesion. With this purpose in mind, it is necessary to study the adhesion of endothelial cells to the biomaterial not only in a static cell culture but also under dynamic conditions, which can better simulate the cell’s physiological environment in vivo. This project develops a methodology to implant cells in cardiovascular grafts under perfusion conditions in vitro, through the design of a bioreactor and the standardization of a static cell culture protocol on SIS sheets and a dynamic culture protocol on SIS grafts.