3D Printing Process for Hydro Gel with the Three-dimensional Micro Tubes to Mimic Vascular Network

A coaxial nozzle printing system is built to investigate the influence of ferric chloride solution to the mechanical strength and shape structure of sodium alginate hollow tube. The optimization process of 3D printing is further determined. The concentration of 2%-4% sodium alginate and the concentration of 4% of calcium chloride is used to print hollow tubes through the coaxial probe. The concentration of 0.25% of atomizing ferric chloride solution is used to reinforced to the calcium alginate hollow tubes. Mechanics experiment prove that the Young's modulus of the reinforced hollow tube (0.4677 MPa±0.279 MPa(2% sodium alginate), 2.0153 MPa±0.221 MPa(3% sodium alginate), 11.684 MPa±0.332 MPa(4% sodium alginate)) are 5.4 times(2%), 14.2 times(3%) and 43.3 times(4%) as the sodium alginate hollow tubes. The reinforced hollow tubes are used to print complex vascular networks such as lattice structure and spiral structure. The vascular networks are encapsulated with hydro gel solution to get the biological scaffold. Perfusion experiment and cell toxicity test show that the scaffolds had good biocompatibility and it is feasible to be effectively transported cells culture medium. Therefore, printed scaffolds can meet the demand of manufacturing large soft tissues in tissue engineering.