Abstract: Objective To investigate the feasibility of building complex hollow tissue in one-step by using the technique of 3D bioprinting. Methods New blends were combined GelMA with Alginate on different concentration, and tested by mechanical examination to explore the feasibility of printable. After bioprinting of hollow tissue with double-layer loading with cells, cell viability assay and perfusion test of printed tissue with microbeads were used. Results Compared with pure group of GelMA （2.38±0.69）×10^-3 MPa and alginate （0.83 ±0.24）×10^-3 MPa, the Young]s mold of combined bioink was （8.78±1.73）×10^-3 MPa.There were significant statistical differences. Based on the combined hydrogel, double-layerd hollow fiber could be printed with the thickness of （62.06 ±0.45）μm of inner wall and （93.78 ±10.25）μm of outer wall. Diameter of inner and outer was （663.66 ±51.74）μm and （976.84±63.44）μm relatively. There were significant differences between inner and outer layer tracked by microbeads with different color. After loading with 3T3 mouse fibroblast cells in inner layer and outer layer in process of bioprinting, live-dead test showed the viability of cells in hollow fibers on day 1 （88.50%±5.8%）,day 3 （85.57%±6.22%） and day 7 （96.29%±2.64%）. Perfused with orange microbeads in 3T3 printed hollow tissue showed good integrity of the wall, and no obvious liquid exudation was observed. Conclusion Using such combined bioinks could fabricate complex hollow tissue with certain perfusion function, in which cells can survive.

Key words: Bioprinting, Hollow tissue, Hygrogels, Alginate, GelMA