An In Situ Depot for Continuous Evolution of Gaseous H Mediated by a Magnesium Passivation/Activation Cycle for Treating Osteoarthritis.

Inflammation is involved in many human pathologies, including osteoarthritis (OA). Hydrogen (H ) is known to have anti-inflammatory effects; however, the bioavailability of directly administered H gas is typically poor. Herein, a local delivery system that can provide a high therapeutic concentration of gaseous H at inflamed tissues is proposed.

In Situ Nanoreactor for Photosynthesizing H Gas To Mitigate Oxidative Stress in Tissue Inflammation.

Hydrogen gas can reduce cytotoxic reactive oxygen species (ROS) that are produced in inflamed tissues. Inspired by natural photosynthesis, this work proposes a multicomponent nanoreactor (NR) that comprises chlorophyll a, l-ascorbic acid, and gold nanoparticles that are encapsulated in a liposomal (Lip) system that can produce H gas in situ upon photon absorption to mitigate inflammatory responses. Unlike a bulk system that contains free reacting molecules, this Lip NR system provides an optimal reaction environment, facilitating rapid activation of the photosynthesis of H gas, locally providing a high therapeutic concentration thereof.