Chronic wound-dressing chitosan-polyphenolic patch for pH responsive local antibacterial activity

Natural or synthetic polymeric films have gained increasing interest in biomedical research due to biocompatibility. In this respect, a nanocomposite film has been developed using the chitosan (C) and polyphenolic tannic acid (T) crosslinking process. The chitosan-tannic acid (CT) films have subsequently functionalized by loading a topical antibiotic (neomycin) drug. The SEM/EDX, FTIR, TGA, and DSC analyses have confirmed CT films. The in vitro antibacterial activity and drug release profiles showed bacterial growth inhibition and pH-responsive drug release. The in vitro drug releases stimulated at mildly acidic pH 5.5 are favorable for normal skin environment and sustained released at higher pH 7.5 indicated potential for chronic wound infection. As a result, the in vivo examined through wound-healing and H&E staining on rat skin incise-area demonstrated complete recovery. The prepared pH active chitosan-tannic acid (CT) dermal patch with or without drug loading can potentially be used in the surgical dressing, wound healing, and dermal drug delivery system.