Multi-scale vascularization strategy for 3D-bioprinted tissue using coaxial core-shell pre-set extrusion bioprinting and biochemical factors.

Three-dimensional bioprinting is a key technology in bioartificial organ production. However, production of bioartificial organs has significant limitations because it is hard to build vascular structures, especially capillaries, in printed tissue owing to its low resolution. As the vascular structure plays a critical role in delivering oxygen and nutrients to cells and removing metabolic waste, building vascular channels in bioprinted tissue is essential for bioartificial organ production. In this study, we demonstrated an advanced strategy for fabricating multi-scale vascularized tissue using a pre-set extrusion bioprinting technique and endothelial sprouting. Using a coaxial precursor cartridge, mid-scale vasculature-embedded tissue was successfully fabricated. Furthermore, upon generating a biochemical gradient environment in the bioprinted tissue, capillaries were formed in this tissue. In conclusion, this strategy for multi-scale vascularization in bioprinted tissue is a promising technology for bioartificial organ production.