Engineered silk fibroin bio-hybrid artificial graft with releasing biological gas for enhanced circulatory stability and surgical performance

Cardiovascular disease (CVD) compromises a range of conditions affecting the heart and blood vessels, and is the leading cause of mortality globally. Vascular grafts are essential in cardiovascular surgical interventions. In clinical treatment, low mechanical durability, thrombosis and hyperplasia are primary failure modes for vascular grafts, highlighting the challenge of developing small-diameter grafts that withstand stress and integrate. A lack of suitable autologous grafts is a main cause of surgery failures. Herein, we have engineered silk fibroin (SF)-based small-diameter artificial grafts (NOeGraft) using a biologically functional polyurethane (PU) template with cost-effectiveness and high feasibility. This template facilitates the generation of biological gases via S-nitrosylation and improves mechanical properties by modulating the secondary structure of SF. Nitric oxide (NO) is one of the most essential biological gases for the cardiovascular system. NO release from NOeGraft suppresses platelet adhesion and smooth muscle cell (SMC) proliferation while scavenging reactive oxygen species (ROS) and promoting epithelial cell growth. Additionally, the suture retention strength of the NOeGraft exceeds 3.4 N. We evaluated the circulatory performance of the NOeGraft using a blood pressure-controllable system, observing no leaks or failures over 2535 min. Cost-effective NOeGraft provides biologically functional and mechanically advantageous solutions for cardiovascular surgeries.