Spray coating of dual antibiotic-loaded nanospheres on orthopedic implant for prolonged release and enhanced antibacterial activity

摘要

Schanz pins are orthopedic implants that are used for the fixation of external fractures. Long-term use of Schanz pins may cause infection, bacterial adhesion, and biofilm formation, and it can also lead to implant rejection. The spray coating or dip coating of an antibiotic directly onto the surface of the implants prior to use is limited to the rapid release of antibiotic for only a short time. To overcome this problem, nanospheres, which are a type of drug-delivery system, were used to control the release of antibiotics. In this research, vancomycin and gentamicin were loaded separately in Poly(lactide-co-glycolide) (PLGA) nanospheres. Nanospheres were prepared by the double-emulsion solvent evaporation method and spray-coated onto the pins. These nanospheres were characterized in terms of size, zeta potential, drug loading, and encapsulation efficiency. The release profiles of antibiotic-loaded nanospheres were determined before investigating thein?vitrorelease of antibiotics from the nanosphere-coated pins. Vancomycin-loaded PLGA nanospheres (VCM-NPs) and gentamicin-loaded PLGA nanospheres (GM-NPs) indicated slightly negative charges, and the sizes were 214.70 and 499.30?nm in diameter, respectively. VCM-NPs and GM-NPs displayed drug-loading contents of 7.12% and 7.97%, respectively. The concentration of vancomycin and gentamicin released from the coated pins were higher than the minimum inhibitory concentration ofStaphylococcus aureusATCC 25423 andEscherichia coliATCC 25922 which could be sustained release for 42 and 49 days, respectively. The coated pins demonstrated superior biocompatibility and long-term antibacterial activity. Furthermore, the strategy utilizes dual antibiotic coating onto the implants via loading in polymeric nanospheres for enhanced antibacterial activity. The data gathered from this study is promising and is capable of combating implant associated infections. Hence, we suggest the use of this strategy for coating other medical devices.