Dongwei Wang
Southwest Jiaotong University, China
Title: Antibiotic release from implant surfaces using immobilized PLGA microspheres
Biography
Biography: Dongwei Wang
Abstract
Postoperative infections are a serious complication in the clinical applications of bone implants. Antibiotic release from the implant surfaces is a promising approach to address this problem. However, a general technique suitable for the incoproration and controlled release of various antibiotics from various implants has not been developed. Here, we report a versatile method for loading and releasing a variety of antibiotics from bone implants. Polylactide-co-glycolide (PLGA) microspheres containing triclosan (an oil-soluble antibiotic) or gentamicin (a water-soluble antibiotic) were separately synthesized by solvent evaporation methods. The microspheres were surface-immobilized on polymethylmethacrylate (PMMA) discs by suspension in water, pipetting on the discs, and vacuum drying. Scanning electron microscopy and total organic content analysis showed that, ~85% of the microspheres remained attached to the disc surfaces even after immersion in phosphate buffered saline for 12 d. Triclosan-loaded PLGA microspheres gave a slow sustained in vitro release, while gentamicin-loaded PLGA microspheres showed initial burst release and a subsequent slow release. After co-culture with E. coli or S. aureus for 24 h, discs carrying triclosan- or gentamicin-loaded PLGA microspheres produced clear inhibition zones, indicating antibacterial activities. This simple method can be applied to a variety of drugs, substrates, and microsphere materials. For example, ciprofloxacin-loaded PLGA microspheres were also successfully immobilized on hydroxyapatite-coated titanium surfaces by this method, and in vitro bacterial culture tests confimred that the resulting samples had antibacterial properties.