Nitric Oxide Release from Antimicrobial Peptide Hydrogels for Wound Healing

Nitric oxide (NO) is an endogenously produced molecule that has been implicated in several wound healing mechanisms. Its topical delivery may improve healing in acute or chronic wounds. In this study an antimicrobial peptide was synthesized which self-assembled upon a pH shift, forming a hydrogel. The peptide was chemically functionalized to incorporate a NO-donor moiety on lysine residues. The extent of the reaction was measured by ninhydrin assay and the NO release rate was quantified via the Griess reaction method. The resulting compound was evaluated for its antimicrobial activity against Escherichia coli, and its effect on collagen production by fibroblasts was assessed. Time-kill curves point to an initial increase in bactericidal activity of the functionalized peptide, and collagen production by human dermal fibroblasts when incubated with the NO-functionalized peptide showed a dose-dependent increase in the presence of the NO donor within a range of 0–20 μM.