A thermosensitive gel loaded with an enzyme and an antibiotic drug for the treatment of periprosthetic joint infection

Biofilms have an important role in the pathogenesis of Periprosthetic Joint Infection (PJI)s and are very likely the main cause in resistance to conventional treatments. In this study, a novel thermosensitive, Pluronic - based gel formulation, containing an enzyme (Serratiopeptidase, SP), an antibiotic drug (Vancomycin HCl, VA) and antibiotic-loaded microspheres (TG-EAM) were prepared and evaluated for their effect against PJI. Viscosity measurements, drug and enzyme release, in vitro enzyme activity and in vitro anti-biofilm activity studies were performed to characterize the formulations. While in vitro drug release studies showed that 74.5% VA was released after 25 d from TG-EAM, the in vitro enzyme activity was measurable for two days. Based on the obtained experimental results, the formulation containing 0.8% (w/v) free VA, 5% (w/v) SP and 40% (w/v) of VA loaded microspheres was chosen as the most suitable formulation for future in vivo studies, as a promising alternative to current standard treatments for PJI.