Pyroptosis-responsive microspheres modulate the inflammatory microenvironment to retard osteoporosis in female mice.

The treatment of osteoporosis and related bone defects remains challenging. This study identifies pyroptosis-driven inflammation as a key disruptor of bone homeostasis. To address this, we develop a magnesium-gelatin composite microsphere scaffold (GelMa/Mg/DMF MS) that exploit pyroptosis blockade and hydrogen-mediated inflammation regulation for osteoporosis treatment. This porous microsphere scaffold is implanted into bone defects to achieve the sustained release of hydrogen gas, magnesium ions (Mg2+), and dimethyl fumarate (DMF). DMF act by activating the nuclear factor erythroid-related factor 2 to prevent osteoblast pyroptosis, and combine with the antioxidant effects of hydrogen, effectively remodel the inflammatory microenvironment and create favorable conditions for the restoration of bone homeostasis. Mg2+ further expedite bone tissue repair. These results demonstrate that the GelMa/Mg/DMF MS effectively reverse inflammatory microenvironments both in vivo and in vitro, resulting in significant tissue repair. These results suggest the combination of hydrogen therapy and pyroptosis blockade as a potential therapeutic strategy.