Coaxial printing micro-diameter polyvinyl alcohol/sodium alginate/tannic acid vascular grafts with interpenetrating...

Cardiovascular diseases remain the leading cause of mortality worldwide, with artificial blood vessels emerging as a promising solution for vascular replacement. However, a critical gap exists in developing implantable, functional small-diameter (≤ 6 mm) grafts with current technology. In this study, we present a novel approach for fabricating micro-diameter (2 mm) hollow vascular grafts using coaxial printing, a technique that enables the precise deposition of multiple materials to form a robust, interpenetrating polymer network. The grafts were composed of polyvinyl alcohol (PVA) crosslinked with tannic acid (TA), and sodium alginate (SA) crosslinked with calcium chloride. Additionally, the artificial blood vessel undergoes treatment using saturated sodium chloride (S-NaCl). These innovative grafts demonstrated exceptional mechanical strength, mimicking the compliance of natural blood vessels and overcoming the compliance issues typically seen in polymeric vascular grafts. Furthermore, the grafts exhibited superior antibacterial properties, enhanced cell adhesion due to their hydrophilicity, reduced platelet activation, and promoted endothelialization. In vivo experiments in mouse showed that the grafts facilitated vascular growth, integrated with surrounding tissues, and displayed anti-inflammatory properties. This novel coaxial printing method with S-NaCl treatment creates PVA/SA/TA vascular grafts, a viable solution for small-diameter grafts with enhanced mechanical, biological, and clinical performance.