Construction of 3D tissue with perfused vessels and capillaries through 3D bio-printing

Due to diffusion limitation, tissues thicker than several hundred micrometers have difficulties in survival and proliferation. 3D bio-printing technology enables to create fluidic channels within tissue structures for appropriate media perfusion. This solution supports viability for the simple tissue model with limited number of cells and scaffold types; however, an additional capillary network is essential for more complex and denser tissues. In this study, we developed a 3D printing method to construct larger fluidic vascular channels in mm-scale and to create adjacent capillary network through a natural maturation process, thus providing a method to connect the capillary network to the large perfused vascular channels. Our bio-printing technology has a great potential in engineering vascularized thick tissues and vascular niches, as the vascular channels are simultaneously created while cells and matrices are printed around the channels in desired 3D patterns.