Chitosan-Based Blended Films for Wound Dressing Applications

Chronic wounds (CW) have numerous entry ways for pathogen invasion and prosperity, which further damages host tissue and hinders tissue remodeling. Essential oils (EOs) exert quick and efficient antimicrobial (AM) action, unlikely to induce bacterial resistance. Cinnamon leaf oil (CLO) is a well-studied EO with strong AM properties. In this work, CLO was added to chitosan (Ch) and polyvinyl alcohol (PVA) solutions. Ch is a natural cationic polysaccharide with antibacterial, anti-inflammatory and regenerative properties. PVA adds flexibility and hydrophilicity to the blend. Ch (100-300 KDa and 9.7±0.6% of DA) and PVA (72 KDa, 88% hydrolysed) films were prepared by solvent casting and phase inversion method (as previously done by the lab). CLO-enriched films included CLO added to Ch shortly before blending, and were based on its minimum inhibitory concentration (MIC; 19.7 µg/mL for S. aureus and 26.2 µg/mL for E. coli). Films chemical composition, thermogravimetric analysis, differential scanning calorimetry, and water absorption capability were tested. Films were successfully built. AM activity, via halo and shake flask tests, was particularly increased with CLO. This study is a first proof of concept that CLO can be dispersed into Ch and PVA films and show bactericidal effects, opening new perspectives for CW therapeutics.