Exosomes are 40-100 nm vesicles that are released into the extracellular environment upon the fusion of multivesicular bodies with the plasma membrane. The biologically cargoes transported by exosomes are diverse. Exosomes are important carriers of signal transmission and interaction between cells. Exosomes are believed to play an important role in tissue repair and bone regeneration. Studies have evaluated that exosomes secreted by cells play an increasingly significant roles in bone tissue engineering and have multiple functions, including regulating immunity, promoting cell proliferation and differentiation, enhancing bone regeneration and angiogenesis. The review analyzes the characteristics and biological properties of different cell-derived exosomes in the bone environment, summarizes their research progress in bone repair, and discusses the challenges and future directions for their application in bone tissue engineering.
外泌体是来自细胞内并通过多囊泡体与质膜融合后释放到细胞外环境的囊泡，直径为40~100 nm。外泌体富含多种生物活性物质，是细胞间信号传递、相互作用的重要物质载体，在组织修复及再生过程中发挥着重要作用。众多的研究表明，细胞分泌的外泌体具有调节免疫、促进细胞增殖分化、促进骨及血管再生的作用，在骨组织工程中发挥着越来越重要的作用。本综述分析骨环境中不同细胞来源的外泌体特征及生物学性能，总结其在骨缺损修复中的研究进展，并探讨其在骨组织工程中应用所面临的挑战及未来发展方向。.
Keywords: bone defect; bone repair; exosome.