Iodine complexed poly(vinyl pyrrolidone) plasma polymers as broad-spectrum antiseptic coatings

Highlights: • Novel, substrate independent plasma polymerized iodine complexed antiseptic coatings. • Optimised use of plasma polymerization to retain high iodine complexation and film stability. • Anti-microbial iodine release from applied material surface, compatible with mammalian cells. Broad spectrum antiseptic materials are in high demand; particularly those suited to coating medical implants, devices and wound dressings. Iodophoric materials are effective broad spectrum anti-bacterial, anti-fungal and anti-viral agents, and in over 150 years of use have not elicited any form of resistance. Therefore, we present the innovative adaptation of the commonly employed clinical iodophor, povidone-iodine into nanoscale coatings using plasma polymerization, to prepare versatile and effective antiseptic coatings suitable for coating medical devices and wound dressings. This process has allowed the substrate independent formation of plasma poly(N-vinyl pyrrolidone) coatings (pPVP) with controllable thicknesses and high-functional group preservation for the complexation of iodine. pPVP coatings applied to wound dressings were found to complex and release iodine in a sustained fashion over a period of 24 h with a total release of ~ 3.5 – 6.0 μg/cm² of iodine over 24 h with high mammalian cytocompatibility (against 3T3 fibroblasts). The coatings exhibited broad spectrum anti-bacterial activity against a clinically relevant panel of microbes responsible for wound infections, including drug resistant strains. This study presents a novel approach to applying substrate independent, biocompatible, broad-spectrum antiseptic coatings that may be broadly applied to coat composite biomedical implants, biomaterials and wound dressings.