Green synthesis of pH-responsive antimicrobial membrane using whole maize grain crosslinked with p-coumaric acid for controlled topical iodine release

Abstract

The increase in fatal diseases associated with microbial activity is posing a great threat worldwide. Numerous techniques are being developed to inhibit the activity or kill the microbes using bioactive materials based on naturally available resources. The current study presents a novel green approach for the synthesis of polymeric membranes based on whole maize grain and p-coumaric acid [poly(p-CA)-cl-M^g-membrane], using a solvent casting method and radical-copolymerization. The prepared membrane was characterized using various techniques including mechanical, antimicrobial, and biomedical properties, showcasing remarkable versatility. The membrane exhibited mechanical flexibility (stiffness: 0.117 N/mm, elongation-at-break: 20%, thickness: 404 μm) and demonstrated impermeability to microbial penetration, high oxygen permeability, and potent antioxidant activity (76.77% radical scavenging). Antimicrobial tests revealed significant inhibition zones against pathogens commonly associated with skin infections, including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Shigella flexneri. Furthermore, the membrane was evaluated as a topical drug delivery system using iodine as a model drug. Drug release studies confirmed a sustained release profile (95.89%) following zero-order kinetics at pH 7.4 over 450 min. The combination of efficient gas exchange, antioxidant protection, and antimicrobial performance highlights the potential of [poly(p-CA)-cl-M^g-membrane] for advanced biomedical applications, including wound care and controlled drug delivery systems.

Graphical abstract