Iodine binding and release from antimicrobial hemostatic polymer foams

Hemostatic macroporous polymer foams synthesized via high internal phase emulsion (HIPE) templating were loaded with iodine to impart broad-spectrum antimicrobial activity. The effects of kaolin loading and iodine content on structure and antimicrobial activity were identified. ATR-FTIR, Raman, and XRD provided detailed insight into the complexation of iodine with the cross-linked PEG-NaAA-PEG macroporous polymer matrix. Iodine was found to incorporate into the foams exclusively as triiodide (I3−) ion coordinated to the various carbonyls throughout the polymer structure. Continued, sustained release kinetics of iodine over 48 h was achieved at high iodine loading, while low iodine yielded burst release kinetics. Broad spectrum antimicrobial activity dependent on iodine loading was demonstrated with significant zone of inhibition against E. coli, K. pneumoniae, P. aeruginosa, and S. aureus. This represents the first report of detailed complexation and sustained release of antimicrobial iodine into highly absorbent, hemostatic, and biocompatible polymeric wound dressing material with potential to combat bacterial resistance in infected wounds.