Design and manufacture of gelatin-alginate scaffolds for tissue engineering based on three-dimensional extrusion bioprinting

Scaffolds play an important role in tissue engineering because they can provide the framework for cell proliferation, tissue creation, and organ regeneration. In this study, we used extrusional three-dimensional (3D) bioprinting technology to generate three scaffolds from gelatin, alginate, and CaCl2, where F6 was a scaffold made from 10% gelatin, 10% alginate, and 60 mM CaCl2; F7 was a scaffold made from 10% gelatin, 10% alginate, and 70 mM CaCl2; and F8 was a scaffold made from 10% gelatin, 10% alginate, and 80 mM CaCl2. They were crosslinked with CaCl2 at 100 mM, aiming to enhance their stiffness. The 3D-printed scaffolds were evaluated for four properties: mechanical testing, FTIR analysis, in vitro cytotoxicity, and cell viability. The results showed that the stiffness of the F8 scaffold was the greatest compared with the other two scaffolds. In general, the crosslinked scaffolds were better than the uncrosslinked scaffolds. For in vitro cytotoxicity test, all the scaffolds showed non-cytotoxic. Moreover, cell viability within the scaffolds printed from cell-laden bio-inks was observed 24 hours after printing and returning to culture conditions. Designing and generating 3D-printed scaffolds is fundamental to future research applications in tissue engineering.