In vitro and in vivo investigations of antibacterial B-TCP/polymer composite enhanced with strontium for bone grafting and photocatalytic applications

Infections, injuries, or surgeries that remove bone can cause bone abnormalities that require specific biomaterials to promote blood vessel growth and bone healing. Composite nanoparticles made of strontium-doped beta-tricalcium phosphate (Sr-doped ß-TCP) are a versatile nanomaterial that could be used in healthcare, especially for repairing bone tissue and tackling antimicrobial resistance (AMR). Strontium, a metal, is known to enhance osteogenesis and fight pathogenic agents. It may also influence bacterial metabolic processes, helping to reduce antibiotic resistance. We produced Sr-doped ß-TCP and its composites using Continuous Plastic Flow Synthesis (CPFS) and autoclaving. Electrospinning created nanofiber composites. FTIR spectroscopy, particle size analysis, zeta potential measurement, XRD, and SEM studies characterized these materials. Their antibacterial activity was tested against Escherichia coli and Staphylococcus aureus with the agar well diffusion assay. For vivo tests, a 3 mm defect was made in the right tibia of rabbits and then treated with the Sr-doped ß-TCP composite. The rabbits were observed at 2, 4, and 6 weeks after surgery. Histological analysis involved decalcifying the specimens, and imaging was performed with an electron microscope. A toxicity assessment of Sr-doped ß-TCP was conducted on BHK-21 fibroblastic cells.