3D-Printed\nHydrogels with Engineered Nanocrystalline\nDomains as Functional Vascular Constructs

Three-dimensionally\nprinted (3DP) hydrogel-based vascular constructs\nhave been investigated in response to the impaired function of blood\nvessels or organs by replicating exactly the 3D structural geometry\nto approach their function. However, they are still challenged by\ntheir intrinsic brittleness, which could not sustain the suture piercing\nand enable the long-term structural and functional stability during\nthe direct contact with blood. Here, we reported the high-fidelity\ndigital light processing (DLP) 3D printing of hydrogel-based vascular\nconstructs from poly(vinyl alcohol)-based inks, followed by mechanical\nstrengthening through engineering the nanocrystalline domains and\nsubsequent surface modification. The as-prepared high-precision hydrogel\nvascular constructs were imparted with highly desirable mechanical\nrobustness, suture tolerance, swelling resistance, antithrombosis,\nand long-term patency. Notably, the hydrogel-based bionic vein grafts,\nwith precise valve structures, exhibited excellent control over the\nunidirectional flow and successfully fulfilled the biological functionalities\nand patency during a 4-week implantation within the deep veins of\nbeagles, thus corroborating the promising potential for treating chronic\nvenous insufficiency.