The bionic code of small-diameter vascular grafts: Gelatin-sodium alginate hydrogel with dual network recapitulates vascular intima functions.

Cardiovascular disease remains one of the leading causes of mortality worldwide, underscoring the urgent need for advanced vascular graft materials. In this study, a small-diameter (inner diameter = 6 mm) dual-network hydrogel vascular graft composed of gelatin and sodium alginate was developed to mimic the native vascular intima. By adjusting the ratio of covalent and ionic cross-linking, the hydrogel containing 15 wt% gelatin exhibited balanced mechanical properties, including suitable tensile strength and elasticity. Rheological analysis revealed that its storage and loss moduli closely matched those of native blood vessels. The material also demonstrated excellent surface hydrophilicity and favorable blood compatibility, characterized by low hemolysis and strong anticoagulant performance. While CCK-8 assays confirmed its ability to support cell proliferation. Overall, this hydrogel-based vascular graft presents a promising strategy for fabricating hemocompatible, mechanically robust grafts for vascular tissue engineering.