The effect of nanoliposomal formulations on Staphylococcus epidermidis biofilm

Abstract

Objective: The aim of the present study was to assess the in vitro antimicrobial activities of nanoliposomal formulations loaded with vancomycin or/and rifampin against the biofilm formed by Staphylococcus epidermidis at 37 °C under aerobic condition.

Materials and methods: Liposomal formulations were prepared by dehydration-rehydration (DRV) method and characterized for size, zeta potential and encapsulation efficacy. The ability of different formulations on eradication of bacterial biofilm was assessed through optical density ratio (OD_r) and the results implicate higher survival rates of S. epidermidis on biofilm. Positive control was defined as an OD_r = 1.0.

Results: The zeta potential of anionic, cationic and PEGylated liposomes was −35 ± 2, 35 ± 1 and 27 ± 2 mV whereas the mean sizes of these liposomal formulations were 145 ± 4, 134 ± 1 and 142 ± 6 nm, respectively. Encapsulation efficacy of rifampin and vancomycin was more than 60% and about 25%, respectively. Cationic liposomal rifampin lowered the OD_r to 0.61 and was the most effective formulations against S. epidermidis biofilm (p < 0.001). The antibiofilm activity of liposomal formulations was concentration- and time-dependent manner.

Conclusion: The results of this study showed that rifampin-loaded liposomes were effective against bacterial biofilm.

• Bacterial biofilm
• liposomes
• rifampin
• Staphylococcus epidermidis
• vancomycin

Acknowledgements

The results described in this article were part of a PharmD student thesis.

Declaration of interest

This work was supported financially by a research grant from the Vice Chancellor for Research of Mashhad University of Medical Sciences, Mashhad, Iran. Authors declare that there is no conflict of interests in this study.