椎间盘退变所继发的椎间盘源性腰痛、椎间盘突出症、椎管退行性狭窄症等疾患是腰腿痛的主要病因，其发病率高、治疗花费大、易复发，是严重影响人类健康的一类疾患。近年来，干细胞移植被用于补充更新退变的髓核细胞，是治疗和逆转椎间盘退变的潜在治疗手段。前期研究中我们发现尿源干细胞（USCs）具有多向分化潜能，且USCs外泌体具有抗衰老、维持细胞活性、逆转细胞退变的作用。本研究拟从尿液中获取USCs，并分离提取其外泌体，采用共培养系统实现USCs向髓核细胞的定向分化，同时利用3D打印技术制得载有髓核样USCs及USCs外泌体的藻酸盐凝胶/PLGA复合生物支架，并实现在退变椎间盘中的移植。本研究首次将USCs—USCs外泌体—藻酸盐凝胶/PLGA复合支架体系引入椎间盘退变的研究当中，试图从分子、细胞、整体水平揭示该体系对退变椎间盘的生物学作用及机制，为临床干细胞治疗椎间盘退变提供新的研究思路，奠定实验基础。

Intervertebral disc degenerative disease(DDD) caused by intervertebral disc degeneration（IVDD）is the main reason for low back and legs pain. On account of its high morbidity、large cost and high rate of relapse, DDD has become one of the most intractable diseases that severely affects human health. Recently, stem cell transplantation which is one of the most effective potential therapis for IVDD has been used to replenish nucleus pulposus cells（NPCs） in the degenerative disc. In previous study，we found that urine stem cells(USCs) has ability of multipotential differentiation and can resist aging，maintain cell viability and reverse degeneration. In this research，we intend to acquire USCs from urine sample and extract its exosome. By using μ-Slide co-culture system and 3D print technology, we attempt to achieve USCs differentiation to NPCs, abtain NPCs-like USCs—USCs exosome—Alginate gel/PLGA composite scaffold. And then, to achieve its transplantation in degenerative intervertebral disc. In this study, for the first time that we introduce NPCs-like USCs-USCs exosome-Alginate gel/PLGA composite scaffold system into the study of IVDD and try to reveal the function and mechanism of this system，providing new research strategy and laying experimental foundation for clinical therapy of IVDD.