Antimicrobial Activity and Biocompatibility of Polyurethane-Iodine Complexes

Polyurethane (PU), one of the most versatile biomedical materials, strongly binds iodine, one of the most effective antiseptics, through the formation of a charge-transfer complex. The PU-Iodine complexes were characterized with UV/Vis study and X-ray photoelectron spectroscopy (XPS) analysis. The new materials evoked potent antimicrobial activity against Gram-negative and Gram-positive bacteria (including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and bacterial spores), fungi, and viruses, as well as inhibited surface bacterial colonization and biofilm-formation. Based on the Kirby-Bauer test, the antimicrobial effects occurred through the slow release of iodine. The iodine release rate can be controlled by the preparation conditions of the PU-Iodine complex. Trypan blue exclusion analysis indicated that PU-Iodine has excellent mammalian cell viability. The PU-Iodine complexes have the potential for a wide range of medical, dental, and other related applications.