Since the concept of tissue engineering was proposed, biocompatible hydrogel materials have attracted the attention of researchers. With the help of three-dimensional (3D) printing technology, precise shaping of hydrogels can be realized. In this paper, we synthesized a cellulosic photosensitive acrylamide (AM)/N,N-methylenebisacrylamide (MBA) hydrogel. With the high-efficiency water-soluble photoinitiator TPO@Tw developed by our research group, the efficient photocuring cross-linking process of the hydrogel can be realized under 405 nm visible light. In consideration of the viscosity, curing mass, curing depth, and break distance of the hydrogel, we screened out hydroxypropyl cellulose (HPC) as the preferred tackifier of the material. The addition of HPC greatly improved the mechanical properties of the hydrogel. The compressive modulus of the optimal sample AM-HPC-5 increased by 709.2% and the tensile strength increased by 76.7% compared with the blank control group. By adding a PEGDA shell to the surface of the material, the water retention capacity of the hydrogel was effectively improved. The water loss rate was greatly reduced. The 3D wooden-pile structure model was printed by a DIW 3D printer. Further, through coaxial extrusion, the microtubule structure that may be applied in tissue engineering was obtained. Cell experiment results showed high biocompatibility of the hydrogel. NIH 3T3 cells could adhere and grow on the surface of microtubules.
Keywords: 3D printing; coaxial printing; hydrogel; photocuring; tissue engineering.