3D Composite Cell Printing Gelatin/Sodium Alginate/n-HAP Bioscaffold

Hydrogel bioprinting has attracted much attention in the field of tissue engineering. However, due to their softness and tendency to shrink, 3D printed hydrogel scaffolds suffer from low printing accuracy and poorer mechanical properties, which makes it difficult to process them into materials with a certain structure. In this study, the gelatin/alginate hydrogel scaffolds were reinforced with nano-hydroxyapatite (n-HAP) and fabricated by CCA-II cell controlled assembly 3D machine. Compared with the pure gelatin sea/alginate scaffold, the addition of nano-hydroxyapatite markedly improved the stability and mechanical strength of the hydrogel scaffolds, and the printing accuracy was improved as well. The addition of n-HAP also adjusted the surface roughness of the scaffolds and improved the biodegradability of the scaffolds. The 3D printed composite hydrogel scaffold showed no cytotoxicity and supported the adhesion and growth of mouse chondrocytes. The printed cell-loaded bio-scaffold had high cell viability, and over 95% viable cells were detected after one week of culture.