间质干细胞（MSC）在组织再生与修复中发挥着重要作用，其应用安全性问题值得关注，寻找能替代MSC新的生物制品或材料并阐明其再生修复作用与机制成为再生医学研究的重要问题。我们已建立了脐带MSC旁分泌的活性成分纳米囊泡（hucMSC-exosome，hucMSC-Ex）的分离方法，初步发现了hucMSC-Ex能修复大鼠热激损伤的皮肤细胞，促进周围正常皮肤细胞向创面的迁移，加快皮肤损伤的愈合。因此，本研究旨在采用细胞与分子技术、蛋白组学技术、生物信息学分析等，完善hucMSC-Ex纯化方法，深入探讨hucMSC-Ex在大鼠皮肤深度烧烫伤模型中的效果与机制，探寻hucMSC-Ex中参与皮肤损伤修复的关键分子。本研究的完成将阐明hucMSC-Ex参与皮肤烧烫伤修复的机制，为皮肤损伤修复提供新的方法和思路，具有潜在应用价值。

Mesenchymal stem cell( MSC) play an important role in tissue regeneration and reparation. The problem of safety in application of MSC should be considered. To investigate a new biologic product or material to substitute for MSC and elucidate their mechanism in tissue regeneration and reparation become an important problem. We have established the method for isolation of human umbilical cord MSC secreted nano exosome (hucMSC-Ex). We have found that hucMSC-Ex can repair heat injury skin cell, promote surrounding normal cells migrate to wound, and promote skin injury healing. Therefore, aim of this study is to consummate purification of hucMSC-Ex and explore the effect and mechanism of hucMSC-Ex in rat deep Ⅱ burn model by celluar and molecular biology, proteomics and bioinformation technology and so on. We will investigate the critical molecules participating in skin wound healing . The mechanism of hucMSC-Ex in tissue regeneration and reparation will be elucidated. This study will provide the base for commercialization and new method of skin deep burn injury healing.