Antimicrobial wound dressings with high mechanical conformability prepared through thiol-yne click photopolymerization reaction

Abstract

Radical mediated photochemical thiol-yne click polymerization of thiol-terminated polyurethane prepolymers, with poly(ethylene glycol) soft segment at two different molecular weights, a propargyl terminated urethane crosslinker and silver salt was utilized to prepare versatile wound dressings containing well-dispersed Ag° nanoparticles produced via in situ reduction of Ag+ ions. The dressings with optimized chemical structure showed desirable fluid handling capacity (up to 4.84 g/10 cm2 d−1) to provide moist environment over damaged tissue. They were permeable to oxygen and carbon dioxide, therefore, the processes related to tissue regeneration of wound bed could be continued without problem. Their appropriate tensile strength (up to 3.87 MPa) and suitable conformability (less than 0.1% permanent set) enabled protection of damaged skin tissue from external physical forces during the healing process, even for wounds present at organs with a high degree of freedom. The proper cytocompatibility of the prepared dressings and their ability to support growth and proliferation of fibroblast cells as determined by wound scratch healing assay showed the potential utility of the dressings to motivate wound healing progression by migration of cells to the damaged area. In addition, these dressings with in situ formed silver nanoparticles exhibited promising antimicrobial activity against different bacterial and fungal strains, and consequently could encourage wound healing process by prevention from infection in the wound site.