Mammalian, plant, and gut microbiota-derived extracellular vesicles as emerging therapeutics for bone diseases.

Bone disorders, including osteoporosis and osteoarthritis, represent a growing global health burden, yet current therapies remain limited by poor targeting efficiency and significant adverse effects. Extracellular vesicles (EVs), nanoscale lipid bilayer particles that mediate intercellular communication, have emerged as promising endogenous nanocarriers with intrinsic biocompatibility and regulatory capacity. This review summarises recent advances in EVs-based therapeutic strategies for bone diseases, focusing on EVs derived from mammalian cells, plants, and the gut microbiota. Particular emphasis is placed on gut microbiota-derived EVs, which have gained increasing attention for their role in regulating bone homeostasis through the "gut-bone axis". By comparing the biological characteristics, advantages, limitations, and disease-specific applicability of EVs from these distinct sources, we highlight their complementary therapeutic potential. Overall, this review provides a concise framework for the rational development and clinical translation of EVs-based precision therapies for bone disorders.