The bactericidal effect of liposomal vancomycin as a topical combating system against Methicillin-resistant Staphylococcus aureus skin wound infection in mice

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of skin infections and treatment is difficult due to its resistance to the most of antibiotics. Although vancomycin is often considered as an antibacterial agent of choice for the treatment of MRSA, its use is limited because of the high side effects. One solution is using liposomal formulation for local drug delivery. The aim of this study was to determine in vitro and in vivo efficacies of liposomal vancomycin as topical use. Methods: To prepare liposomal vancomycin, the ammonium sulfate gradient using remote loading and freeze-thaw methods was applied. Then, synthesized nanoliposomes were evaluated in terms of particle size, morphology, stability, and encapsulation efficiency. Minimum inhibitory concentration (MIC) of synthesized nanoliposome against MRSA was detected. The cytotoxicity of synthesized nanoliposome was evaluated using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Finally, the topical antibacterial activity of each formulation was tested against MRSA-infected skin wound model in mice. Results: High encapsulation efficiency was achieved for all synthesized nanoliposomes. The results of in vitro and in vivo showed that liposomal vancomycin was more effective than free vancomycin. Also, synthesized nanoliposome showed no cytotoxicity on human epidermoid cell line. Conclusion: The results showed that synthesized nanoliposome could be applied as a great topical antimicrobial construct for treatment of MRSA skin infections.