Hydrogen Sulfide Responsive Phototherapy Agents: Design Strategies and Biological Applications

Hydrogen sulfide (H2S) is one of the critical gasotransmitters, which play important roles in regular physiological processes, especially vital signaling pathways. However, fluctuations endogenous H2S concentration can be linked to serious health problems, such as neurodegenerative diseases, cancer, diabetes, inflammation, cardiovascular and hypertension. Thus, it has attracted a great deal attention therapeutic applications, specifically field phototherapy. Photodynamic therapy (PDT) photothermal (PTT) are two subclasses phototherapy, utilize either reactive oxygen species (ROS) or local temperature increase upon irradiation photosensitizer (PS) realize action. Phototherapies offer unique advantages compared conventional methods; thus, they highly promising popular. One design principles followed new generation PSs build activity-based PSs, stay inactive before getting activated by disease-associated stimuli. These activatable dramatically improve selectivity efficacy therapy. In this review, we summarize small molecule nanomaterial-based PDT PTT agents that selectively initiate their cytotoxic effect. We incorporate single mode along with synergistic and/or multimodal photosensitizers combine more than approach. Additionally, H2S-responsive theranostic agents, imaging at same time, highlighted. Design approaches, working principles, biological applications for each example discussed detail.