Self-assembled mesoporous bioglass polyphenol nanozymes for repairing musculoskeletal trauma.

Volumetric Musculoskeletal Trauma (VMST), which is characterized by volumetric muscle loss accompanied by bone injury, poses a significant challenge to regenerative medicine. While current therapies primarily focus on the individual regeneration of muscle or bone, there is no systematic and integrated treatment strategy. In this study, we developed a CuMBG-PA, a copper-doped nanozyme based on mesoporous bioactive glass (MBG) and procyanidin (PA), for integrated muscle and bone repair of VMST. CuMBG-PA self-assembles into a stable polyphenol network via Cu-PA coordination bonds, enhancing PA stability and reactive oxygen species-scavenging capacity. In vitro and in vivo experiments demonstrated that CuMBG-PA promoted osteogenesis and myogenesis while exhibiting high biocompatibility and antibacterial activity. Single-cell RNA-sequencing results revealed that CuMBG-PA synergistically induces stem cell differentiation and promotes tissue repair through multiple myoskeletal shared metabolic pathways. Mechanistically, CuMBG-PA exerts its beneficial effects by increasing the number of Proteoglycan 4 (Prg4) + fibro/adipogenic progenitor cells (FAPs), which highly express fibronectin and insulin-like growth factor. In addition, PRG4 regulates immune cells, removes overactivated muscle satellite cells, reduces muscle fibrosis, and promotes functional recovery during regeneration. In summary, this work demonstrates that the novel self-assembled CuMBG-PA nanozyme represents a potential biomaterial-based strategy for integrated muscle and bone repair in VMST.