Supramolecular Carbon Monoxide-Releasing Peptide Hydrogel Patch

Carbon monoxide (CO) is recently accepted as a therapeutic molecule that exhibits remarkable biological actions, including anti-inflammation, antiapoptosis, and cytoprotection, at a physiological level. For clinical use without the side effect of tissue hypoxia, which arises from the uncontrolled administration of CO in the human body, CO-releasing molecules (CORMs) are developed to ensure safe and efficient CO-delivery. Herein, a syringe-injectable CO-releasing peptide hydrogel (COH) and a corresponding bioadhesive hydrogel patch (COHP), developed by rational supramolecular chemistry, to enhance the therapeutic efficacy of CO with controllable CO-release to a specific tissue is report. The injectable COH is prepared by self-assembly of the CORM-attached peptides with a gel-forming diphenylalanine-derivative, resulting in fibrillar networks and exhibiting prolonged CO-release compared with CORMs. Furthermore, Ca2+-chelating and mussel-derived catechol-functionalized peptides are introduced to afford a mechanically rigid, bioadhesive COHP that elicits cytoprotective and anti-inflammatory activities. The supramolecular COHP can be utilized in the efficient CO-delivery to the site of interest by conformal contacts, making it a promising scaffold for biomedical applications.