Bone tissue regeneration has become increasingly important due to the challenges posed by critical-sized injuries, pathology, or disease. Tissue engineering offers a promising approach to repair and regenerate damaged bone tissue. To achieve this, emerging technologies such as 3D bioprinting have been proposed for designing microarchitectures through layer-by-layer extrusion using different biopolymers or hydrogels such as alginate and gelatin, which, due to their malleability and biocompatibility, facilitate the generation of cell-laden scaffolds that could restore bone defect functionality.

This work aimed to synthesize a 3D bioprinting scaffold with a bioink combination of alginate–gelatin with and without fetal osteoblasts. The scaffold's characterization by FTIR showed the characteristic signals of the bioink components, while SEM analysis showed the porous structure morphology of the 3D-printed scaffold and the cell–material interaction.

The biological response when osteoblasts were seeded over the surface and use as part of the bioink showed good adhesion and biocompatibility over the 21 days of culture. Moreover, alizarin red staining showed that osteogenic factors improved the quantity of calcium deposits in both assays for calcium deposit evaluation.

In conclusion, our results showed that the bioink based on alginate and gelatin allows for a stable 3D-printed scaffold, supporting the osteoblasts' viability and cell growth and bone extracellular matrix deposition. The authors want to thank the financial support of CONAHCYT for the scholarship granted for the master study of DVH with CVU: 1190428, and the financial support given by the DGAPA-UNAM-PAPIIT IN202924 project.