Recent development of hydrogen sulfide-releasing biomaterials as novel therapies: a narrative review.

Hydrogen sulfide (H2S) has been reported as an endogenous gasotransmitter that contributes to the modulation of a myriad of biological signalling pathways, which includes maintaining homeostasis in living organisms at physiological concentrations, controlling protein sulfhydration and persulfidation for signalling processes, mediating neurodegeneration, and regulating inflammation and innate immunity, etc. As a result, researchers are actively exploring effective approaches to evaluate the properties and the distribution of H2S in vivo. Furthermore, the regulation of the physiological conditions of H2S in vivo introduces the opportunity to further study the molecular mechanisms by which H2S regulates cellular functions. In recent years, many H2S-releasing compounds and biomaterials that can deliver H2S to various body systems have been developed to provide sustained and stable H2S delivery. Additionally, various designs of these H2S-releasing biomaterials have been proposed to aid in the normal conduction of physiological processes, such as cardioprotection and wound healing, by modulating different signalling pathways and cell functionalities. Using biomaterials as a platform to control the delivery of H2S introduces the opportunity to fine tune the physiological concentration of H2S in vivo, a key to many therapeutic applications. In this review, we highlight recent research works concerning the development and application of H2S-releasing biomaterials with a special emphasis to different release triggering conditions in in vivo studies. We believe that the further exploration of the molecular mechanisms underlying H2S donors and their function when incorporated with various biomaterials will potentially help us understand the pathophysiological mechanisms of different diseases and assist the development of H2S-based therapies.