Chaenomeles speciosa-derived extracellular vesicles accelerate fracture healing via orchestrating immuno-angiogenic coupling

Abstract

Purpose Fracture nonunion remains a major orthopaedic challenge, and dysregulation of the bone immune microenvironment is increasingly recognized as a key pathological driver. Chaenomeles speciosa is a medicinal plant with documented anti-inflammatory properties, making it a promising candidate for immune-modulatory therapy. This study investigated whether extracellular vesicles derived from Chaenomeles speciosa could reshape the immune microenvironment to promote fracture healing. Methods Single-cell RNA sequencing was performed on human nonunion tissues to characterize cellular heterogeneity. Network pharmacology and molecular docking analyses were used to identify potential therapeutic targets of Chaenomeles speciosa. Extracellular vesicles were isolated by ultracentrifugation and characterized by transmission electron microscopy. Macrophage polarization, angiogenesis, and inflammatory signaling were assessed in vitro using RAW 264.7 macrophages and human umbilical vein endothelial cells. Bone regeneration was evaluated in a rat femoral fracture model using micro-computed tomography and histology. Results Single-cell RNA sequencing revealed M1 macrophage dominance and enhanced M1-mediated communication with osteoblasts and endothelial cells in nonunion tissues. The IL-17 signaling pathway and matrix metalloproteinase-3 were identified as key therapeutic targets. Isolated extracellular vesicles exhibited excellent biocompatibility, promoted M2 macrophage polarization, attenuated inflammation, and enhanced angiogenesis in vitro. In the rat fracture model, treatment with these extracellular vesicles significantly accelerated bone regeneration, as evidenced by increased bone bridging and callus formation. Conclusion These findings establish a macrophage-centric pathological network in nonunion and demonstrate that Chaenomeles speciosa-derived extracellular vesicles promote bone repair through immuno-angiogenic coupling, supporting their potential as a multi-targeted therapeutic strategy for fracture healing.