Transparent ciprofloxacin-povidone antibiotic films and nanofiber mats as potential skin and wound care dressings

Water insoluble monohydrochloride monohydrate free ciprofloxacin (Cipro) antibiotic was incorporated in polyvinylpyrrolidone (PVP) polymer matrix by using acetic acid co-solvent in water. The resultant solutions were cast into fully transparent antimicrobial films. Proper concentrations of acetic acid eliminated in situ crystallization of the antibiotic and the resultant phase separation upon solvent evaporation. The solutions could also be electrospun into nanofiber mats (non-transparent). Presence of residual PVP-bound acetic acid in dry PVP films induced unprecedented levels of plasticity (stretching capacity) and softness to the films. Additionally, PVP-bound acetic acid also acted as an antiseptic. Antibacterial properties of the films and fiber mats were confirmed on Escherichia coli and Bacillus subtilis (growth and viability). Films and nanofiber mats demonstrated promising wound resorption characteristics by using in vivo full-thickness excisional skin wound healing mice model. Nanofiber mats were resorbed much faster than transparent films. Wound exudate absorption in the films and resorption rate of the nanofiber mats were dependent on the starting acetic acid concentrations. The fact that PVP/Cipro solutions in aqueous acetic acid can be used either to produce transparent soft films or nanofiber mats renders this process highly suitable for the fabrication of new-generation potential dressings for wound management and care.