Biothiol-triggered H2S release from a near-infrared fluorescent H2S donor promotes cutaneous wound healing

Hydrogen sulfide (H2S) plays crucial roles in antioxidation, anti-inflammation, and cytoprotection. Despite substantial progress in the design and synthesis of activatable H2S donors, methods for high-precision detection and imaging of released H2S in living systems have been lacking. In this study, a biothiol-activated near-infrared (NIR) fluorescent H2S donor, PRO-ST, was developed for real-time visualization of H2S release. PRO-ST consists of a dicyanoisophorone-based NIR fluorescence moiety (TCOO), a biothiol-trigger moiety (4-isothiocyanate benzyl alcohol), and a sulfur-source group (thiophosgene). PRO-ST exhibits high NIR fluorescence enhancement (45-fold), outstanding H2S release efficiency (73%), controllable H2S release (60 min), and excellent cell compatibility. These distinctive features enable PRO-ST to be applied in visualizing H2S release in cells, zebrafish, and mice. Moreover, PRO-ST exhibits excellent performance in visualizing real-time anti-inflammation and wound healing enhancement in biological systems, as confirmed by in situ visualization of H2S release. Thus, PRO-ST provides a versatile and effective method to detect and visualize H2S release, elucidate the mechanisms underlying wound healing, or optimize interventional therapy.