Bacterial adherence to ofloxacin-blended polylactone-coated self-reinforced L-lactic acid polymer urological stents

OBJECTIVE: To determine whether ofloxacin coating has any effect on bacterial adherence to bioresorbable self-reinforced L-lactic acid polymer (SR-PLLA) urological stents. MATERIALS ANS METHODS: SR-PLLA stents were coated with epsilon-caprolactone/L-lactide copolymer blended with ofloxacin at three different concentrations of ofloxacin (0.5, 2 and 5% w/w). The adherence of five bacterial strains (Pseudomonas aeruginosa, Enterococcus faecalis, Proteus mirabilis and two strains of Escherichia coli) to the coated SR-PLLA stents was analysed. Uncoated stent pieces were used as controls. The effect of ofloxacin coating on bacterial growth in the microenvironment of the stent pieces was also analysed. RESULTS: Ofloxacin coating prevented bacterial adherence to SR-PLLA stent material; this effect correlated significantly with the ofloxacin concentration of the caprolactone coating. Ofloxacin coating reduced the amount of bacteria in the microenvironment of the stent, but because of natural resistance, ofloxacin coating had little effect on E. faecalis. CONCLUSION: Except for E. faecalis, ofloxacin coating may reduce stent-associated infections. However, further studies are needed to confirm its biocompatibility and efficacy in clinical use.