Iron-Doped Brushite Bone Cement Scaffold With Enhanced Osteoconductivity And Antimicrobial Properties For Jaw Regeneration

Critical success factors for the restoration of jaw defects depend on scaffolds with high levels of osteoconductivity and antimicrobial properties due to the special oral microenvironment. Brushite cement (dicalcium phosphate dihydrate, DCPD) is a bioceramic with good self-setting properties, plasticity, bioabsorbability, and biocompatibility, but with poor osteoconductive and antimicrobial properties. It has been reported that elemental iron doped into DCPD is effective for overcoming this critical deficiency. Herein, iron-doped dicalcium phosphate dihydrate (Fe-DCPD) was prepared and its physicochemical properties characterized. The time required for FeDCPD to set was significantly prolonged, and its in vitro degradability increased compared with DCPD. Additionally, the effects of Fe-DCPD on cell adhesion, migration, proliferation, alkaline phosphatase activity, biomineralization, its antimicrobial properties and relative expression of osteogenic genes in MC3T3-E1 cells were evaluated. In addition, the ability to promote restoration of the jaw in vivo was evaluated, to provide the experimental basis for its preclinical application. The incorporation of iron promoted the adhesion, proliferation, and migration of MC3T3-E1 cells, and increased their ALP activity and expression of osteogenic-related genes. Furthermore, both agar plate and broth anti-bacterial tests revealed that Fe-DCPD displayed a significantly greater antibacterial effect on typical Gram-negative and Gram-positive bacteria than DCPD. The in vivo study indicated that Fe-DCPD scaffolds displayed superior antimicrobial and bone repair properties in a rabbit jaw defect. The study established that DCPD doped with iron is a suitable modification for conferring antimicrobial and osteoconductive properties on scaffolds. Thus, the Fe-DCPD scaffold has excellent potential for applications in jaw repair.