Multistructured vascular patches constructed via layer-by-layer self-assembly of heparin and chitosan for vascular tissue engineering applications

With the growing prevalence of cardiovascular diseases, developing applicable vascular patches has become a pressing issue. In this work, we used layer-by-layer (LbL) self-assembly technique to construct vascular patches of polyelectrolyte multilayer (PEM) by alternately depositing heparin and chitosan onto the substrate polyurethane-coated decellularized scaffold (PU/DCS). The biocompatibilities of these PEM vascular patches were evaluated, and the in vivo performance in a porcine model was investigated with B ultrasound, Doppler spectrum and computed tomography angiography (CTA). Compared with the substrate PU/DCS, the PEM vascular patches had improved biocompatibility, including decreased hemolysis rate, prolonged in vitro coagulation time and enhanced resistance to platelet adhesion. They also showed the enhancement in the attachment and proliferation of endothelial progenitor cells. Additionally, CTA indicated that the PEM vascular patches could maintain the long-term patency of the surgical arteries (5 months) while the substrate PU/DCS blocked the surgical arteries even at 2-week implantation. Therefore, the PEM vascular patches showed great potential in vascular tissue engineering applications. This work also provided a feasible strategy to construct multistructured vascular patches and other biomaterials.