Endothelium-Protective, Intimal Hyperplasia-Resistant PCL/KAT Scaffold for Vascular Implants

Small-diameter vascular grafts (SDVGs) have great potential in the treatment of cardiovascular diseases. However, thrombosis and restenosis of SDVGs, caused by incomplete endothelium and abnormal smooth muscle cell proliferation, limit their clinical applications. Hydrogen sulfide (H₂S) is a crucial signaling molecule in the cardiovascular system, playing a vital role in physiological processes such as blood pressure regulation, angiogenesis, and the reduction of vascular hyperplasia, as well as exerting anti-inflammatory effects. In this study, a human hair keratin-based H₂S donor was synthesized and coelectrospun with poly(ε-caprolactone) to develop an H₂S-releasing vascular graft. The graft effectively promoted the growth and migration of HUVECs and suppressed the proliferation of HUASMCs by releasing H₂S. Interestingly, the grafts accelerated endothelium formation under shear stress and protected them from oxidative stress. In vivo experiment also demonstrated that the endothelial layer regenerated without detectable thickening of the smooth muscle layer after 1 month of implantation, which was attributed to the H₂S-mediated effect. Taken together, this study provided strategies for the tissue remolding of small-diameter vascular grafts.