Promising antibacterial effect of impregnated nanofiber matswith a green nanogel against clinical and standard strains ofPseudomonas aeruginosa and Staphylococcus aureus

Background and Aim : Pseudomonas aeruginosa and Staphylococcus aureus are two importantpathogens that cause many maladies such as skin diseases in humans. Resistance to commonantibiotics is a major challenge for health care systems worldwide; new green antibacterial agentshave become crucial. In this study, ingredients of Mentha longifolia essential oil were firstinvestigated; pulegone (۴۶.۹۷%), eucalyptol (۱۲.۲۲%), piperitenone (۶.۱۳%), carvone (۴.۱۶%),and limonene (۳.۴۲%) were identified as five major ingredients. Electrospun nanofibers ofpolycaprolactone-alginate nanofibers with ۱۸۸ (±۳۶) nm diameter were then prepared.Methods : The nanofibers were characterized using ATR-FTIR analysis, SEM analysis, and watercontact angle meter. They did not show cytotoxic effects on HFFF۲ cells, a human skin normalcell line. After that, a nanoemulsion-based nanogel of M. longifolia EO was prepared andphysically impregnated on the surface of the nanofibers mats. Antibacterial effects of the preparedprototype at three concentrations (۲.۵, ۵, and ۱۰ mg/mL) with exposure times of ۱, ۳, and ۲۴ hwere investigated against clinical and standard strains of P. aeruginosa and S. aureus.Results : At a ۵ mg/mL concentration with ۱ h exposure, the growth of a standard strain of P.aeruginosa ∼۸۰% was decreased. After increasing exposure time to ۲۴ h, growth of both standardand clinical strains ∼۹۰% reduced. Furthermore, at a ۱۰ mg/mL concentration with exposure timesof ۳ and ۲۴ h, ∼۱۰۰% reduction in the growth of all exanimated bacteria strains was observed.Conclusion : The chemical composition of M. longifolia EO was first investigated using GC-MSanalysis. Electrospun nanofibers of polycaprolactone-alginate nanofibers were then prepared; theydid not show cytotoxicity on a normal human skin cell line (HFFF۲). After that, nanoemulsionbasednanogel of M. longifolia EO was prepared and physically impregnated on the surface of thenanofibers mats. Finally, the antibacterial effects of the prepared prototype against clinical andstandard strains of P. aeruginosa and S. aureus were investigated; their growth was reduced to ~۰%. As the green ingredients of the prepared prototype and its promising efficacy, it could thus beused as a potent antibacterial agent in wound dressing or cleaning pads.