Promising antibacterial effect of impregnated nanofiber mats with a green nanogel against clinical and standard strains of Pseudomonas aeruginosa and Staphylococcus aureus

Pseudomonas aeruginosa and Staphylococcus aureus are two important pathogens that cause many maladies such as skin diseases in humans. Resistance to common antibiotics is a major challenge for health care systems worldwide; new green antibacterial agents have become crucial. In this study, ingredients of Mentha longifolia essential oil were first investigated; pulegone (46.97%), eucalyptol (12.22%), piperitenone (6.13%), carvone (4.16%), and limonene (3.42%) were identified as five major ingredients. Electrospun nanofibers of polycaprolactone-alginate nanofibers with 188 (+/- 36) nm diameter were then prepared. The nanofibers were characterized using ATR-FTIR analysis, SEM analysis, and water contact angle meter. They did not show cytotoxic effects on HFFF2 cells, a human skin normal cell line. After that, a nanoemulsion-based nanogel of M. longifolia EO was prepared and physically impregnated on the surface of the nanofibers mats. Antibacterial effects of the prepared prototype at three concentrations (2.5, 5, and 10 mg/mL) with exposure times of 1, 3, and 24 h were investigated against clinical and standard strains of P. aeruginosa and S. aureus. At a 5 mg/mL concentration with 1 h exposure, the growth of a standard strain of P. aeruginosa similar to 80% was decreased. After increasing exposure time to 24 h, growth of both standard and clinical strains similar to 90% reduced. Furthermore, at a 10 mg/mL concentration with exposure times of 3 and 24 h, similar to 100% reduction in the growth of all exanimated bacteria strains was observed. The prepared prototype could thus be used as a green potent antibacterial agent as a wound dressing and cleaning pad.