Magnesium Particles Coated with Mesoporous Nanoshells as Sustainable Therapeutic‐Hydrogen Suppliers to Scavenge Continuously Generated Hydroxyl Radicals in Long Term

Abstract Sustainable supplementation of massive molecular‐H 2 is considered to be the most effective therapy for long‐term elimination of excessive hydroxyl radicals (·OH) in vivo, but has not been achieved so far. In this work, it is demonstrated that magnesium microparticles (Mg MPs) coated with mesoporous nanoshells can achieve the long‐term and high‐efficient generation of therapeutic hydrogen in physiological condition for ·OH scavenging. The as‐proposed magnesium@mesoporous SiO 2 core–shell microparticles (Mg@p‐SiO 2 MPs) are synthesized by developing a modified Stöber method using acetone as the solvent, and they exhibit shell thickness ( d )‐dependent H 2 release behavior due to the barrier effect of nanoshells on both the occurrence of Mg–water reaction and H 2 diffusion. Consequently, they are able to provide vast quantities of H 2 molecules dissolved in body fluid with a rate controlled by d over a long period. A simulation model is established which well explains and further predicts the dependence of H 2 release behavior on d , and the long‐term protection of cells from oxidative damage by Mg@p‐SiO 2 MPs is also experimentally validated. As the H 2 concentration and effective duration in medium can be adjusted by dosage and d , Mg@p‐SiO 2 MPs are promising for accurate H 2 drug delivery in vivo.