The Development of Gelatin-Based Bio-Ink for Use in 3D Hybrid Bioprinting

Numerous researchers have studied 3D hybrid bioprinting technology, as it appears to be a viable option for producing cellular constructs with clinical relevance. This technology uses a co-printing process with high strength bio-plastics and cell-laden bio-inks. The bio-inks used in this technology should be easily printable and provide good biological environment for artificial tissue regeneration. In this research, we present a gelatin-based bio-ink for 3D hybrid bioprinting. We prepared a variety of gelatin mixtures and evaluated them in terms of their printability. We also investigated the effects of using hyaluronan and glycerol as additives. The results showed that hyaluronan and glycerol enhanced the spatial resolution and uniformity of the printed patterns. We determined the optimal composition for the bio-ink and then conducted 2D and 3D cell patterning tests. The results showed that our bio-ink can produce a line width of approximately 200 mu m, and multiple types of cells can be positioned precisely in 3D structures. We also conducted a cytocompatibility test with NIH3T3 fibroblast. This test showed the processability of our bio-ink with living cells. Finally, we printed an actual-size, human ear-shaped construct. These experiments suggest that the proposed gelatin-based bio-ink is well suited for applications to 3D hybrid bioprinting technology.