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Small-diameter vascular grafts fabricated from synthetic biodegradable polymers exhibit beneficial mechanical properties but often face poor regenerative potential. Different tissue engineering approaches have been employed to improve tissue regeneration in vascular grafts, but there remains a requirement for a new generation of synthetic grafts that can orchestrate the host response to achieve robust vascular regeneration. Vascular stem/progenitor cells (SPCs) are mostly found in quiescent niches but can be activated in response to injury and participate in endothelium and smooth muscle regeneration during neo-artery formation. Here, we developed a functional vascular graft by surface immobilization of stem cell antigen-1 (Sca-1) antibody on an electrospun poly(ε-caprolactone) graft (PCL-Sca-1 Ab). PCL-Sca-1 Ab promoted capture and retainment of Sca-1+SPCs in vitro.In rat abdominal aorta replacement models, PCL-Sca-1 Ab stimulated in vivorecruitment of Sca-1+SPCs, and drove SPCs differentiation towards vascular cell lineages. The origin of infiltrated Sca-1+SPCs was further investigated using a bone marrow transplantation mouse model, which revealed that Sca-1+SPCs originating from the resident tissues and bone marrow contributed to rapid vascular regeneration of vascular grafts. Our data indicated that PCL-Sca-1 Ab vascular grafts may serve as a useful strategy to develop next generation cell-free vascular grafts.

Cardiovascular diseases (CVDs) are among the leading causes of mortality and morbidity worldwide. Nitric oxide (NO) is a signalling molecule that plays a vital role in protecting and regulating cardiovascular function and homeostasis. Despite several successful outcomes of exogenous supplementation of NO for cardiovascular disease therapy, a great challenge lies in controlled and long-term delivery due to the short half-life and instability of NO. Recently, increasing attention has been paid to the in situconversion of endogenous NO donors catalysed by functional surfaces. Based on bioinspired and biomimicking strategies, a series of surface functionalization methods for cardiovascular stents has been successfully developed. By further combining NO catalysis with other biofunctionalities, improved endothelium healing and long-term patency can be anticipated.