Bactericidal Activity of Copper Oxide Nanocomposite/Bioglass for in Vitro Clindamycin Release in Implant Infections Due to Staphylococcus aureus

Abstract

Background: In recent years, bioactive bioceramics such as bioglass and hydroxyapatite (HA) have been introduced as a remarkable development in the field of medicine due to their bio-adaptability, non-toxicity, and persistence, in vivo. They have many potential applications in the repair of bone defects and hence they have attracted significant interest from scholars. Objectives: The aim of this study was to synthesize inorganic matrix CuO-based bioglasses and evaluate their antibacterial activity against aerobic bacterial infections in bone implants. Methods: Nano-composite samples of silica-based bioactive glass, 60S BG with nano-powder CuO, were synthesized using the sol-gel method and then assessed with regard to their antibacterial properties against Staphylococcus aureus using well diffusion agar. The samples included BG58S (58%SiO2, 36%CaO, 6%P2O5), BG/10CuO (58%SiO2, 26%CaO, 6%P2O5, 10%CuO), and BG/20CuO (48%SiO2, 26%CaO, 6%P2O5, 20%CuO). To evaluate their bioactivity, the prepared samples of BG/20CuO, BG/10CuO, and BG58S were immersed in sim-ulated body fluids (SBF). The surface morphology and structure of the samples before and after immersion in the SBF were char-acterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), respectively. Then, the BG/20CuO and BG/10CuO samples were loaded in clindamycin, an antibiotic widely used in the treatment of osteomyelitis, and their release profiles were studied in phosphate buffer solution. Results: It was observed that the growth inhibition zone increased through clindamycin release due to the increasing CuO per-centage in the nanocomposite of bioactive glass. The bioactivity of the nanocomposite/bioglass with CuO was superior to that of bioglass alone. In this study, the BG/20CuO sample showed a sustained release of clindamycin, which is sufficient for a drug delivery system. Conclusions: Increasing the Cu nanoparticles in bioactive glass samples leads to the release of Cu 2+ , which has a positive effect on the antibacterial mechanism, as well as decreasing the cultured Staphylococcus colonies found on the bioglasses. Therefore, it seems that the nanocomposite/bioglass of CuO is a promising option for aerobic bacterial inhibitor systems in common bone implant infections.