Synthesis, characterization and evaluation of antibacterial properties of silver- fluoride hydroxyapatite powder on coating of 316L steel external fixator by sol gel method

The external fixators (pins) have many applications in orthopedic surgeries in the field of trauma. The success of clinical applications of external fixators has decreased due to their infection after orthopedic surgery. Meanwhile, the loosening of the pin embedded in the bone occurs due to the presence of bacteria and the formation of biofilm on the pin, and this infection will progress to the joint surface of the bone and the pin. Among the different techniques to improve the bone-pin interface in external fixation, coating the pins with antibacterial materials proved to be the most effective. Accordingly, the present study has focused on synthesis by sol gel method, structural, and antibacterial evaluations of Ag-FHA structure. The FESEM images and Mapping analysis confirmed the nano-scale size and homogeneous dispersion of particles in the Ag-FHA structure, respectively. In addition, the FTIR results indicated the hydroxyapatite formation in obtained structure. The XRD analysis has shown that the conversion of the amorphous phase to the crystalline phase occurred in all structures at a temperature of about 300 to 350 ° C , and the formation of the HA phase is increased and completed at 600 ° C. The antibacterial study was done by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination. The obtained results showed that the Ag 0.2-FHA could significantly inhibit the growth of Staphylococcus aureus and Escherichia coli.