Prolonged antibiotic release by PLGA encapsulation on titanium alloy

Deep infection after artificial joint arthroplasty is a devastating complication. Local antibiotic delivery in revision surgery is useful in preventing the recurrence of infection. The present study investigates whether encapsulated antibiotic-loaded plasma-sprayed titanium alloy hip prosthesis materials that use biodegradable poly(lactic-co-glycolic acid) (PLGA) copolymer extend the duration of steady antibiotic release without a burst release. Two kinds of antibiotic (vancomycin and cefuroxime) and various concentrations and number of layers of PLGA encapsulation are investigated to determine the optimal antibiotic release. The antibiotic release is quantified with an elution test. The extracts were collected at 1, 6, and 12 hours and daily after 24 hours for antibiotic concentration analysis using a spectrophotometer. The degradation of PLGA correlated with the antibiotic release rate is characterized by weight change, pH value, and morphology observation. The effective antibiotic release durations for single-layer 15% PLGA in the vancomycin group, single-layer 15% PLGA in the cefuroxime group, double-layer 15% PLGA in the cefuroxime group, and one layer of 30% PLGA over one layer of 15% PLGA are 5, 7, 10, and 17 days, respectively. PLGA encapsulation can provide an extended antibiotic release of up to 2.5 weeks without a burst release. The release can be further extended in vivo to reach clinical effectiveness.