Diarylcyclopropenones: Modular, Tetherable, Light-Triggerable Reservoirs of Carbon Monoxide in Crosslinked Hydrogels.

Carbon monoxide (CO) is an endogenously produced gasotransmitter with established anti-inflammatory and cytoprotective effects, yet its therapeutic exploration and application remain limited by challenges associated with controlled delivery. We recently demonstrated that diphenylcyclopropenone (DPCP) serves as a highly efficient, visible-light-triggered CO-generating motif when incorporated into polymeric micelles. Here, we investigate whether DPCP functions as a modular CO source by integrating it into chemically diverse crosslinked hydrogel networks. Hydrogels were selected as a representative solid biomaterial platform due to their widespread use in implants, tissue engineering, and cell culture. We demonstrate that DPCP-mediated CO generation is preserved across a range of hydrogel compositions, and that hydrogels allow for spatiotemporal control over CO release. However, CO release into solution depends on hydrogel network properties and chemistry. These results establish diarylcyclopropenones as a modular, tetherable, light-triggerable reservoir of CO gas and hydrogels as a tunable platform for its use.