Sense and Release: A Thiol-Responsive Flavonol-Based Photonically Driven Carbon Monoxide-Releasing Molecule That Operates via a Multiple-Input AND Logic Gate

Abstract

Molecular structures capable of intracellular information processing that couple responses from biomarker signals to the release of drug molecules represent intelligent delivery systems. Herein we report a chemophotonically driven, sense-of-logic carbon monoxide-releasing molecule (SL-photoCORM). This extended flavonol motif operates via an AND logic gate by first sensing the cellular environment via detection of thiols and then releasing CO when triggered with visible light and O₂. Overall, this approach couples the detection of a cellular redox biomarker with the ability to release a small-molecule gasotransmitter known to trigger pathways involved in pro- and anti-inflammatory effects in a dose-dependent manner. Significantly, the fluorescence properties of the flavonol-based SL-photoCORM produce a series of chemophotonic input responses via two photochromatic switches (blue-to-green and green-to-colorless), leading to trackability and spatiotemporal control of CO release. Examination of the O₂ requirements of the CO release step revealed that the SL-photoCORM is suitable for use under conditions of variable cellular levels of O₂. These combined properties within a single-molecular framework advance the field of CO-releasing molecules by providing feedback on the diversity and complexity of the cellular environment prior to CO release.