Despite the remarkable progress in biofabrication, the vascularization of large-sized tissue scaffolds remains a great challenge for tissue engineering. The lack of effective capillary vessels in the scaffold can result in cellular necrosis due to the lack of oxygen and nutrients. Integrating capillary vessels in scaffolds is critical to maintaining cellular metabolic functions and the ultimate success of engineering large-scale tissues and organs. This paper demonstrates a novel hybrid biofabrication method that combines coaxial electrospinning and extrusion-based bioprinting to fabricate microtube-embedded hydrogel scaffolds. The porous microtubes mimicked the capillary morphology and were embedded between layers of 3D printed sodium alginate scaffold to function as a microchannel diffusion system. The dye diffusion test showed that the microtubes enhanced the mass transport within the scaffold.
