Cell-induced Intracellular Controlled Release of Membrane Impermeable Cysteine from a Mesoporous Silica Nanoparticles-based Drug Delivery System

Intracellular thiols are of vital importance for controlling the homeostasis of live cells.1 For example, glutathione (GSH) is one of the agents responsible for the reducing milieu of various cell types. Recent studies have highlighted the key role of GSH in several physiological processes, such as DNA synthesis, microtubular-related processes, immune functions, and protection against oxidative damage induced by free radicals and other toxicants.The low intracellular concentration of GSH has been attributed to several chronic inflammation disorders, which often leads to cancerous, neurodegenerative, and cardiovascular maladies. A variety of therapeutic methods in promoting GSH biosynthesis have been developed for the treatment of these diseases. The success of these approaches hinges upon the availability of intracellular cysteine (Cys). A mesoporous silica nanoparticle-based intracellular cysteine delivery system that could be induced and regulated by cell-produced natural antioxidants was synthesized