Antibacterial alginate hydrogel coated composite bone cement beads to treat osteomyelitis and regeneration

Invasion of bacteria or pathogens into the bone causes bone infection leading to inflammation and damage to bone tissue. The current treatment modalities for chronic osteomyelitis is antibiotic treatment using bone cement beads. Continuous release of antibiotics from bone cements for a longer duration resulting in bacterial resistance. To overcome these limitations, antibiotics incorporated hydrogel-coated composite bone cement beads provide effective antibacterial activity, possess an ECM-like environment for healing and localized drug delivery. Therefore, we developed a ciprofloxacin incorporated alginate hydrogel (C-AL) coated tetracalcium Phosphate-Nano diopside (BCD) composite bone cement beads (C-AL-BCD) to treat bone infections and promote regeneration. The incorporation of Nano-diopside into the bone cement beads promotes both osteogenesis and angiogenesis. The prepared beads were characterized using SEM, FTIR, XRD, and EDAX analysis. The in vitro biocompatibility, osteogenic activity of the prepared BCD beads was studied using biomineralization, RUNX2, and OPN expression in dental follicle stem cells, demonstrating an enhanced osteogenic mineralization and markers expression. Similarly, in vitro angiogenic studies of the BCD beads were studied using Tube formation, and Migration assay in endothelial cells and showed an enhanced angiogenic activity. Furthermore, biocompatibility, antibacterial, and anti-biofilm activities of the C-AL-BCD beads were studied and exhibited good biocompatibility, antibacterial and anti-biofilm activity. In vivo antibacterial activity was analysed in the Drosophila melanogaster fly model, with C-AL-BCD beads showing a higher survival rate than infected groups. Thus, this developed C-AL-BCD beads could be an ideal system for the synergistic treatment of bone infections and vascularized bone regeneration.