Biomimetic Prussian blue nanozymes with enhanced bone marrow-targeting for treatment of radiation-induced hematopoietic injury

There is an urgent medical need to develop effective therapies that can ameliorate damage to the radiation-exposed hematopoietic system. Nanozymes with robust antioxidant properties have a therapeutic potential for mitigating radiation-induced hematopoietic injury. However, enhancing nanozyme recruitment to injured tissues in vivo while maintaining their catalytic activity remains a great challenge. Herein, we present the design and preparation of a biomimetic nanoparticle, a mesenchymal stem cell membrane camouflaged Prussian blue nanozyme (PB@MSCM), which exhibits biocompatible surface properties and demonstrates enhanced injury site-targeting towards the irradiated murine bone marrow niche. Notably, the constructed PB@MSCM possessed redox enzyme-mimic catalytic activity and could scavenge overproduced reactive oxygen species in the irradiated bone marrow cells, both in vitro and ex vivo. More importantly, the administration of PB@MSCM significantly mitigated hematopoietic cell apoptosis and accelerated the regeneration of hematopoietic stem and progenitor cells. Our findings provide a new targeted strategy to improve nanozyme therapy in vivo and mitigate radiation-induced hematopoietic injury.