A "Vascular Band-Aid" strategy for proactive inhibition of post-anastomotic vascular complications

Vascular anastomosis frequently fails in elderly patients or those with chronic comorbidities due to aberrant inflammation and disordered repair, ultimately leading to stenosis or occlusion. Inspired by the dual action of a conventional band-aid: physical protection and microenvironmental intervention, we herein develop a "Vascular Band-Aid" strategy designed to target the anastomotic site through interface intervention and proactively accelerate incised vessel healing to prevent adverse events. This band-aid, featuring a bioactive interface, is constructed through stepwise modification of aligned poly(L-lactide-co-ε-caprolactone) nanofibrous membrane with copper-chelated tannic acid complexes (via noncovalent binding) and poly-L-lysine molecules (via Michael-type addition and Schiff-base reactions). The resulting coating markedly increases fiber surface roughness, enhances membrane wettability, surface charge and protein adsorption, owing to the introduction of abundant -NH₂ and phenolic hydroxyl groups. These features improve cell affinity and drive endothelial mature through cell-matrix interactions and mechanotransduction, while alleviating inflammation-induced cytotoxicity. When applied at anastomotic sites in an arterial intimal hyperplasia model, the band-aid provides durable structural support, modulates inflammation and accelerates cell proliferation to enhance vascular regeneration, effectively demonstrating its efficacy in preventing anastomotic failure. This surface-engineering strategy also establishes a generalizable paradigm for other tissue interfaces where postoperative healing remains a critical barrier.