Endothelial cells seeding obtained from stem cells on PTFE vascular prosthesis

The purpose of this paper was to study the possibility to prepare small diameter bypass grafts with similar biological functions of natural vessels, improving the endothelial cells (EC) attachment to a popytetrafluoroethylene (PTFE) vessel (with modified inner surface) derived from stem cells (SC). Methods. This study investigated the possibility that PTFE prosthesis, imbibed with barium-alginate, may enhance EC attachment. The barium-alginate was in a solution containing heparin, fibronectin and vascular endothelial growth factor (VEGF). The barium alginate was also coated with poly-L-lysine. Moreover, the possibility to obtain a high number of EC with high moltiplication rate from bone marrow SC CD34+, inducing a maturation with VEGF, was studied. The cell attachment to a PTFE prosthesis and their permanence on the inner prosthesis wall was controlled in vitro after a saline solution flow through at 10 cm/s/15min. The prosthesis, treated with barium-alginate and with heparin coated or not with poly-L-lysine were implanted in the jugular vein and in the carotid of the sheep. Results. The prosthesis imbibed with barium alginate coated with poly-L-Lysine containing heparin had shown in vivo and in vitro antithrombotic capacity. The poly-L-lysine coating enhances cell adhesion, and at the same time, heparin reduces the thrombotic effect due to its positive electric charge. The barium alginate remains stable inside the prosthesis wall and it was observed after 4 months from the implant in artery bypass. Conclusion. The conclusion is drawn that it is possible to obtain from SC CD34+ a high number of EC and that these attach easily on PTFE prosthesis when these were imbibed with barium-alginate cated with poly-L-lysine