Poly(vinyl alcohol)-gelatin crosslinked by silane-functionalized guanidyl-hydroxyurethane oligomer as contact-killing non-leaching antibacterial wound dressings.

The present work aims to prepare efficient wound dressing with noncytotoxicity, proper mechanical strength, and the ability to preserve a hygienic environment over wounded skin tissue. To fulfill this goal, the synthesis of a novel silane crosslinking agent with antibacterial guanidinium chloride functional group is considered. The resulting reagent was applied to make a series of film-type stable crosslinked networks composed of poly(vinyl alcohol) and gelatin. The potential protection of wounds from external forces was confirmed, as these films had a very good tensile strength (16-31 MPa) and good elongation (54-101%) under dry conditions. The good dimensional strength of dressings was preserved after hydration with simulated wound exudates. Based on the calculated fluid handling capacity of the prepared dressings (2.43 to 3.54 g 10-1 cm-2 day-1), they were suitable for treating wounds with 'light' to 'moderate' exudate volume. All the prepared dressings showed very good biocompatibility, as determined by the high viability of fibroblast cells directly contacted with dressing (over 80%) or leachates extracted from them (over 90%). In addition, dressings functionalized with guanidinium groups could effectively kill representative gram-positive and gram-negative bacterial strains.&#xD.