Skin and muscle permeating antibacterial nanoparticles for treating Staphylococcus aureus infected wounds

Majority of the chronic wounds are infected with bacteria like Staphylococcus aureus (S. aureus). The deep tissue infections are difficult to treat using topical antibiotics, due to their poor tissue penetration. In order to treat S. aureus deep tissue infections we have developed an antibiotic delivery system using chitosan nanoparticles (CNPs). To enhance their tissue penetration these CNPs were further coated using lecithin (CLNPs). Antibiotic tigecycline was loaded into chitosan nanoparticles (tCNPs) and then coated with lecithin to generate lecithin coated tigecycline loaded chitosan nanoparticles (tCLNPs). The prepared nanoparticles were characterized using DLS, SEM, TEM and FT-IR. The prepared CNPs, tCNPs, CLNPs and tCLNPs have the size range of 85 +/- 10, 90 +/- 18, 188 +/- 5 and 235 +/- 20 nm, respectively. The tCLNPs shows more sustained release pattern of tigecycline. The antibacterial activity of the developed nanoparticles was confirmed against laboratory and clinical strains of S. aureus using in vitro and ex vivo experiments. The ex vivo skin and muscle permeation study ensures the enhanced delivery of tigecycline to the deeper tissue. The prepared nanoparticles were hemo-compatible and cyto-compatible. Our study suggests that the prepared tCLNPs can be effectively used for the treatment of S. aureus infected wounds. (c) 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 797-807, 2016.