Solid lipid nanoparticles containing vancomycin: preparation, characterization and in vitro anti-Staphylococcus aureus biofilms activity

Coagulase-negative staphylococci and Staphylococcus aureus are the most common cause of nosocomial infections and can induce a wide spectrum of diseases associated with remarkable morbidity and mortality. Biofilms of staphylococci are intrinsically resistant to conventional antibiotics and, being commonly associated with implanted medical device, such as catheters and vascular grafts, have the potential to cause blood-stream infections. The paper describes the preparation and characterization of vancomycin-loaded Solid Lipid Nanoparticles (SLNs) and in vitro studies of the inhibition of Staphylococcus aureus ATCC 29213 biofilms in the presence of this nanoparticle system. Methods. The vancomycin-loaded SLNs were prepared by microemulsion method. Physicochemical and technological characterization of SLNs was performed concerning drug loading amount, particle size and zeta potential measurements. In vitro microbiological studies, were carried out by methylthiazotetrazolium (MTT) method. Results. The results of studies showed that the vancomycin-loaded SLNs have a better activity in the inhibition of Staphylococcus aureus biofilms respect to free vancomycin. At concentration of 10 μg/ml, the SLNs containing vancomycin were three times more active than free dru