Abstract 218: Biofunctional Tissue-engineered Vascular Grafts Induce Vascular Regeneration

Vascular graft has proven to be an effective strategy for the treatment of cardiovascular diseases. However grafts made solely from synthetic polymers cannot satisfy the clinic requirements in terms of low long-term patency, because they only provide a simple structural or physical replacement without the biological functions. In order to address the issue, we aim to fabricate vascular grafts which could mimic native extracellular matrix (ECM) in terms of both physiological structure and bio-functions. Different types of strategies and techniques have been explored to realize this purpose, including graft structure optimization, surface/interface functionalization, and controlled delivery of vascoactive molecules.Up to now, we have successfully fabricated a kind of vascular grafts with dual surface functions of anti-thrombogenicity and rapid endothelialization. Through structural optimization, the problem of limited cellularization in vascular grafts has been effectively resolved, and thus the vascular regeneration as well as the homeostasis has been improved. Furthermore, incorporation of some specific cytokines (such as Dickkopf-3) into the micro/nano- fibrous vascular grafts could enhance the migration vascular progenitor cells (VPCs) into the grafts and further induce the differentiation of them, contributing to endothelialisation and intima/media formation. In addition, vascular grafts loaded with exosomes derived from mesenchymal stem cells have been successfully prepared, and delivered exosomes exhibited immunomodulation function which is very important for the vascular regeneration and inhibition of calcification.