3D bioprinting for vascular grafts and microvasculature

Cardiovascular disease is the world’s leading cause of death, and there is a substantial clinical need for transplantable blood vessels. Through tissue vascular engineering technology, large blood vessel grafts with significant clinical effects have been synthesized. However, synthesizing vascular valves, small vessels up to 6 mm in diameter, and capillary networks up to 500 μm in diameter remains challenging due to the lack of precise manufacturing techniques. In particular, constructing a microvascular network in thick tissue is the technical bottleneck of organ transplantation. Three-dimensional (3D) bioprinting is a computer-assisted layer-by-layer deposition method that can deposit cells and biomaterials at a predetermined location, according to an accurate digital 3D model, to build a delicate and complex bionic structure. This review discusses the progress and limitations of 3D bioprinting in preparing large vessels and valves, small-diameter vessels, and microvascular networks. This paper focuses on improved printing technology and innovative bio-ink materials. The future application of 3D bioprinting is prospected in generating artificial blood vessel grafts and vascularized organs with full biological function.