Usnic acid (UA) is a lichen secondary metabolite useful for the treatment of burn wounds thanks to the antimicrobial activity particularly toward strains responsible for the burn infections. However, the poor solubility is the main factor limiting limits its activity and thus use in health care products. Adhesive polymeric films were designed to enhance UA bioavailability to the wounded tissue. Three different hydrogel films were prepared by casting method differing from the polymer used: NaCMC 2% alone (F1), mixed to PVP K90 0.1% (F2) or to Carbopol 971P 0.1% (F3). Ex vivo experiments performed on pig skin samples showed suitable adhesion capacity of these films. The in vitro release test performed using the extraction cell showed that F2 is able to afford the highest UA concentrations. A deep characterization allowed to highlight that UA is present in F2 composition in non-crystalline, more soluble, form. The in vitro antibacterial activity assayed by agar diffusion analysis showed that F2 is the most effective film against UA sensitive bacteria as S. Epidermidis, E. Faecalis, B. Cereus and S. Pyogenes. Cytotoxicity assays on human keratinocytes and fibroblasts showed that cells viability is not compromised. Wound healing experiments on these two cell lines showed the lack of cicatrizing properties of UA.
Bioadhesive polymeric films based on usnic acid for burn wound treatment: Antibacterial and cytotoxicity studies
Pagano, Cinzia;Ceccarini, Maria Rachele;Calarco, Paola;Conte, Carmela;Ricci, Maurizio;Perioli, Luana
2019
Abstract
Usnic acid (UA) is a lichen secondary metabolite useful for the treatment of burn wounds thanks to the antimicrobial activity particularly toward strains responsible for the burn infections. However, the poor solubility is the main factor limiting limits its activity and thus use in health care products. Adhesive polymeric films were designed to enhance UA bioavailability to the wounded tissue. Three different hydrogel films were prepared by casting method differing from the polymer used: NaCMC 2% alone (F1), mixed to PVP K90 0.1% (F2) or to Carbopol 971P 0.1% (F3). Ex vivo experiments performed on pig skin samples showed suitable adhesion capacity of these films. The in vitro release test performed using the extraction cell showed that F2 is able to afford the highest UA concentrations. A deep characterization allowed to highlight that UA is present in F2 composition in non-crystalline, more soluble, form. The in vitro antibacterial activity assayed by agar diffusion analysis showed that F2 is the most effective film against UA sensitive bacteria as S. Epidermidis, E. Faecalis, B. Cereus and S. Pyogenes. Cytotoxicity assays on human keratinocytes and fibroblasts showed that cells viability is not compromised. Wound healing experiments on these two cell lines showed the lack of cicatrizing properties of UA.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
