Smart triboelectric bilayer vascular graft with integrated drug delivery and real-time hemodynamic sensing

Effective vascular remodelling hinges on matching degradation with native vessel regeneration and compliance, alongside promoting endothelialization and reducing intimal hyperplasia. While synthetic grafts are effective for large-diameter vascular defects, small-diameter vascular defects still lack a viable alternative due to their low patency. Thus, a potentially advanced vascular graft mimicking the structural and functional properties of the native artery remains a promising strategy. Here, we developed a drug-incorporated porous bilayer scaffold using a combination of salt-leaching and electrospinning techniques. The inner layer composed of a highly porous composite poly(glycerol sebacate)/ polycaprolactone (PGS/PCL) polymers loaded with anti-thrombogenic drug Dipyridamole (DPA) (PGS/PCL/DPA), further sheathed with an electrospun PCL/silk fibroin (SF) membrane incorporated with endothelial cell promoting Resveratrol (RES) drug (PCLSF/RES). This dual-layer structure ensures controlled scaffold degradation synchronized with native vessel remodelling, thereby exhibiting a sustained drug release. Further the bilayer scaffold presents superior mechanical properties, with enhanced suture retention strength, improved burst pressure and relative tensile strength. Additionally, upon drug loading, it has been confirmed hemocompatible, with augmented anti-thrombogenic capability. Moreover, in-vitro studies demonstrated increased endothelialization with migration and tube formation ability, with a reduced Smooth muscle cell (SMC) viability. Notably, the bilayer scaffold also exhibits a triboelectric sensing capability, enabling real-time hemodynamic monitoring. Thus, these results position this bilayer scaffold as a smart, multifunctional candidate for the construction of functional small-diameter vascular grafts (SDVGs).