AimsInduction heating is a noninvasive, nonantibiotic treatment modality that can potentially be used to cause thermal damage to the bacterial biofilm on the metal implant surface. The purpose of... Show moreAimsInduction heating is a noninvasive, nonantibiotic treatment modality that can potentially be used to cause thermal damage to the bacterial biofilm on the metal implant surface. The purpose of this study was to determine the effectiveness of induction heating on killing Staphylococcus epidermidis from biofilm and to determine the possible synergistic effect of induction heating and antibiotics.MethodsS. epidermidis biofilms were grown on titanium alloy (Ti6Al4V) coupons for 24 hours (young biofilm) and seven days (mature biofilm). These coupons with biofilm were heated to temperatures of 50 degrees C, 55 degrees C, 60 degrees C, 65 degrees C, 70 degrees C, 80 degrees C, and 90 degrees C for 3.5 minutes and subsequently exposed to vancomycin and rifampicin at clinically relevant concentrations.ResultsFor the young biofilm, total eradication was observed at 65 degrees C or higher for 3.5 minutes followed by 24 hours of vancomycin 10 mg/l and rifampicin 1 mg/l. For the mature biofilm, total eradication was observed at 60 degrees C for 3.5 minutes followed by 24 hours of vancomycin 10 mg/l and rifampicin 1 mg/l. Total eradication was also observed at 60 degrees C for 3.5 minutes followed by 24 hours of vancomycin 1 mg/l and rifampicin 1 mg/l followed by anotherthermal shock of 60 degrees C for 3.5 minutes (two thermal shocks).ConclusionInduction heating of Ti6Al4V coupons is effective in reducing bacterial load in vitro for S. epidermidis biofilms. Induction heating and antibiotics have a synergistic effect resulting in total eradication of the biofilm at 60 degrees C or higher for clinically relevant concentrations of vancomycin and rifampicin. Show less
