Evaluation of the Characteristics of Digital Light Processing 3D-Printed Magnesium Calcium Phosphate for Bone Regeneration.

Recent advancements in three-dimensional (3D) printing technology, particularly digital light processing (DLP) 3D printing, have enabled the customization of bone substitutes with specific shapes that match bone defect sizes and geometries. Magnesium calcium phosphate (MCP) has gained considerable attention due to its strong mechanical properties, degradability, and ability to promote bone regeneration. In this study, we prepared MCP samples with five different molar ratios via DLP 3D printing. We analyzed the physicochemical properties of these five groups, including phase compositions and microstructures, which were examined using X-ray diffraction and scanning electron microscopy, respectively. Additionally, we assessed the effects of MCP on material density and shrinkage. Biaxial flexural strength and degradation rate were evaluated; biological properties were examined through WST-8 analysis and alkaline phosphatase activity assays. Among the tested samples, MCP1/1 exhibited the highest strength. A higher proportion of magnesium phosphate in MCP corresponded to an increased degradation rate. Cell response observations in the WST-8 assay indicated that cell proliferation was better in the MCP1/1 group than in the other groups on days 4 and 7 of culturing. Alkaline phosphatase activity assays demonstrated that MCP1/1 exhibited higher activity than calcium phosphate. Our findings suggest that MCP1/1 can be used effectively in bone-tissue-engineering applications.