Effect of Phosphate Phase Incorporation on 3D-Printed Hydrogel Scaffolds: Towards Customizable Bone Graft Materials

Bone defects remain a significant clinical challenge, creating a severe need for advanced biomaterials for tissue regeneration. This study addresses this need by developing and characterizing 3D-printed composite hydrogels composed of alginate, gelatin, and resorbable calcium phosphates (monetite and brushite) for bone tissue engineering. A series of scaffolds was fabricated using extrusion-based 3D printing and systematically evaluated for morphology, porosity, mechanical strength, swelling, degradation, and in vitro mineralization. The inclusion of calcium phosphates enhanced the mechanical stability and promoted mineral deposition within the hydrogel matrix, while cytocompatibility was assessed using LIVE/DEAD cell viability assays. These findings indicate that the developed 3D-printed hydrogels are bioactive, constituting promising, customizable scaffolds suitable for bone regeneration, offering a viable alternative to traditional bone grafts. The results support further investigation of these materials for clinical applications in bone tissue engineering.