Triggered and Tunable Hydrogen Sulfide Release from Photogenerated Thiobenzaldehydes.

Hydrogen sulfide (H2 S) has been identified as an important cell-signaling mediator and has a number of biological functions, such as vascular smooth muscle relaxation, neurotransmission, and regulation of inflammation. A facile and versatile approach for H2 S production initiated by light irradiation and controlled by reaction with an amine or an amino acid was developed. The donor was synthesized in a one-pot reaction, and simple crystallization led to a yield of approximately 90 %. The synthetic strategy is scalable and versatile, and the H2 S donors can be expressed ina number of different molecular and macromolecular forms, including crystalline small-molecule compounds, water-soluble polymers, polystyrene films, and hydrogels. The H2 S donors based on polystyrene film and hydrogel were used as cell-culture scaffolds. The H2 S donor based on water-soluble polymer was applied in photocontrolled inhibition of P-selectin expression on human platelets and subsequent regulation of platelet aggregation. This study provides the simplest controllable H2 S source to study its biological functions. The developed materials are also new therapeutic platforms to deliver H2 S, as there is no accumulation of toxic byproducts, and the donor materials from polystyrene films and hydrogels can be readily removed after releasing H2 S.