Study on 3D printing technology and mechanical properties of a nano-enhanced composite hydrogel bio-ink

Traditional bio-inks are mostly limited in application due to their low-mechanical strength or complex cross-linking curing methods. In this study, a nanocomposite hydrogel bio-ink [gelatin-alginate-montmorillonite (GT-AT-MMT)] for 3D bioprinting is designed based on the thermo-sensitive properties of GT, the advantages of ionic crosslinking of sodium AT, and the shear thinning and toughening mechanism of nano-MMT. The 3D printing of the bio-ink with variable AT content is optimised, and the tensile, compressive, and creep properties of the 3D printed structure are studied. Results show that GT-AT-MMT bio-ink has good printability, and its mechanical properties are enhanced with increased AT content. The tensile modulus of the GT-4% AT-MMT sample can reach 0.533 MPa, which has a minimum creep deformation of 0.311 mm under the same load condition. Therefore, GT-AT-MMT bio-ink provides a new possibility for the development of 3D bioprinting, which will offer many opportunities in fields such as tissue engineering, drug delivery, and regeneration medicine.