外泌体是一种外细胞囊泡，含有多种成分，如DNA、RNA、脂质和蛋白质，对细胞间通讯起着重要作用。大量研究已经证明外泌体通过促进间充质干细胞中成骨相关基因和蛋白质的表达，对骨再生起到重要作用。然而，外泌体的低靶向性和短循环半衰期限制了它们的临床应用。为了解决这些问题，已经开发出不同的递送系统和生物支架。水凝胶是由三维亲水性聚合物组成的可吸收生物支架。它不仅具有优异的生物相容性和超强的机械强度，而且还可以为内源性细胞的生长提供适宜的营养环境。因此，外泌体和水凝胶的组合可以提高外泌体的稳定性，保持其生物活性，并在骨缺损部位实现外泌体的持续释放。玻尿酸是细胞外基质的重要成分，对细胞分化、增殖、迁移、炎症、血管新生、组织再生、伤口愈合和癌症等多种生理和病理过程都起着关键作用。近年来，基于玻尿酸的水凝胶已被用作骨再生的外泌体递送系统，并取得了积极的效果。本文主要总结了玻尿酸和外泌体促进骨再生的潜在机制，以及基于玻尿酸的水凝胶作为骨再生外泌体递送装置的应用前景和挑战。版权所有©2023邓、王和安。

Exosomes are extracellular vesicles (EVs) containing various ingredients such as DNA, RNA, lipids and proteins, which play a significant role in intercellular communication. Numerous studies have demonstrated the important role of exosomes in bone regeneration through promoting the expression of osteogenic-related genes and proteins in mesenchymal stem cells. However, the low targeting ability and short circulating half-life of exosomes limited their clinical application. In order to solve those problems, different delivery systems and biological scaffolds have been developed. Hydrogel is a kind of absorbable biological scaffold composed of three-dimensional hydrophilic polymers. It not only has excellent biocompatibility and superior mechanical strength but can also provide a suitable nutrient environment for the growth of the endogenous cells. Thus, the combination between exosomes and hydrogels can improve the stability and maintain the biological activity of exosomes while achieving the sustained release of exosomes in the bone defect sites. As an important component of the extracellular matrix (ECM), hyaluronic acid (HA) plays a critical role in various physiological and pathological processes such as cell differentiation, proliferation, migration, inflammation, angiogenesis, tissue regeneration, wound healing and cancer. In recent years, hyaluronic acid-based hydrogels have been used as an exosome delivery system for bone regeneration and have displayed positive effects. This review mainly summarized the potential mechanism of HA and exosomes in promoting bone regeneration and the application prospects and challenges of hyaluronic acid-based hydrogels as exosome delivery devices in bone regeneration.Copyright © 2023 Deng, Wang and An.