Plant-based biocomposite films as potential antibacterial patches for skin wound healing

Natural polymers represent a promising family of materials for the fabrication of skin wound dressings that can improve the healing process and the protection against pathogens. In this work, we present the preparation of natural polymeric films combining two plant-based polymers: zein, an alcohol-soluble protein from corn, and pectin, a hydrophilic polysaccharide of the plant cell wall. The effect of two different forms of pectin - low methoxy and amidated low methoxy - on the resulting biocomposite was investigated. Glycerol was added to improve the mechanical performances. The degradation assay in various buffers and thermogravimetric analysis highlighted the tendency of the composite films to degrade faster in water than the pure zein films, due to the pectin ability to be released from the protein matrix in an aqueous environment. Drug release was performed, confirming the results obtained with previous analyses. Antimicrobial assays indicated the ability of the developed biocomposite patches to inhibit the growth of three pathogens (Escherichia coli, Staphylococcus aureus, Candida albicans). The biocompatibility was confirmed in vitro with primary human dermal fibroblasts via MTS assay and cell morphology inspection. The results indicate the great potential of the presented plant-based biomaterials as drug delivery systems for the treatment of skin wounds.