Decellularized Fish Swim Bladder Extracellular Matrix–Polycaprolactone Composite Material for Application in Small‐Diameter Vascular Grafts

The high incidence of cardiovascular diseases has led to an increasing demand for small-diameter vascular grafts. Polycaprolactone (PCL) is a commonly used synthetic polymer material in the construction of vascular grafts. However, PCL alone has limited bioactivity, which may affect its blood-contacting and tissue responses when used in small-diameter vascular grafts. Fish swim bladder-derived extracellular matrix (FSB-ECM) contains bioactive components such as collagen and has been investigated as a cardiovascular biomaterial, although its mechanical properties are limited. In this study, fish swim bladder-derived dECM was incorporated into PCL by electrospinning to fabricate a series of small-diameter vascular grafts. The study first confirmed that dECM was successfully loaded onto PCL fibers and significantly improved the hydrophilicity and degradation performance of the material. Based on the in vitro and ex vivo evaluations, the 15% PCL-dECM (3:7) formulation was selected for further in vivo testing because it showed a favorable balance of mechanical properties and hemocompatibility, including low platelet activation. Subsequent in vivo evaluation in a rat abdominal artery implantation model demonstrated that this dECM-modified graft achieved a 100% patency rate. Furthermore, it exhibited significant anti-inflammatory effects and was conducive to the organized deposition of extracellular matrix components, such as collagen and elastic fibers. This work successfully developed a novel small-diameter vascular graft that possesses both excellent bioactivity and mechanical properties. Our findings offer a promising strategy and a solid experimental foundation, supporting the future clinical translation of small-diameter vascular grafts.