ABSTRACT
PURPOSE: To compare the antibiotic release kinetics of the implant coated with antibiotic-impregnated polymers MATERIALS AND METHODS: Authors used polylactic acid (PLA) and polylactic-co-glycolic acid (PLGA) as the biodegradable carriers, gentamicin sulfate as the antibiotic and Steinmann pin as the implant. Ten Steinmann pins were coated with gentamicin of each 10, 20 and 30% mixture of PLA or PLGA for the elution kinetics study. In the elution study, total 60 coated implants were incubated in 10 mL of phosphate buffered saline (PBS) at 37 delta C and sampled at 6 hrs, 1, 3, 6, 9, 12, 15, 20, and 25 days. Assays were performed with fluorescence polarization immunoassay. Statistical analysis was done with SAS release 2.01. RESULTS: Released concentration of GM decreased with time. Minimum inhibitory concentration was maintained until 6th day on PLA 10% subgroup, 9th day in the 20 and 30% subgroups, until 6th day on PLGA 20% subgroup, and 3rd day in the 10 and 30% subgroups. Released concentrations were significantly higher in all PLA subgroups than in PLGA as a parameter of sampled time (all p<0.05). There was no statistical difference between PLA 20 and 30% subgroup after 12th sampled day (p=0.2636). CONCLUSION: PLA-GM group showed higher effective concentration for longer time than PLGA-GM group. 20 and 30% subgroups of PLA-GM showed prolonged maintenance of minimum inhibitory concentration compared with 10% subgroup, but there was no difference between the two groups.