Evaluation of sodium alendronate drug released from TiO2 nanoparticle doped with hydroxyapatite and silver–strontium for enhancing antibacterial effect and osteoinductivity

Abstract

Hydroxyapatite (HA) nanocrystalline coatings on implants increase bone/implant joint fusion, but bacteria grow on hydroxyapatite-coated implants and cause infections. To solve this problem, silver (Ag), strontium (Sr), and chitosan were used to modify the surface of the titanium dioxide nanoparticles (TNPs) coated with hydroxyapatite. Ag was used for antimicrobial properties, and Sr was used to control drug release and increase the ossification of titanium implants. Chitosan (Chit) is a natural polymer with good biocompatibility, low toxicity, and strong antibacterial properties. The results show that HA + Sr + Ag + Chit coating causes controlled and long-term release (more than 16 days) of the alendronate sodium drug, an osteoporosis drug, from the implant. Electrochemical corrosion studies reveal that the Sr + Ag + HA + Drug + Chit coating on titanium dioxide nanoparticles has reduced the corrosion penetration rate compared to pure titanium dioxide nanoparticle (TNP). The cytotoxicity analysis results show that the TNP + Sr + Ag + HA + Drug sample has the highest cell viability, equal to 99.3%. Microbial study shows that coated TNPs have more inhibition of Staphylococcus aureus growth than uncoated TNPs. Among the coated TNP samples, TNP samples with HA + Sr + Ag coating had the highest inhibition of bacterial growth.