牙髓干细胞、外胚间充质干细胞裸鼠体内分化的实验研究

目的：将免疫磁珠STRO＋-1的牙髓干细胞（DPSC）和外胚间充质干细胞（EMSC）与支架材料复合,观察在裸鼠体内移植后的分化能力,为干细胞分化能力研究提供依据.方法：收集免疫磁珠STRO＋-1的DPSC和EMSC,将其与陶瓷化骨复合移植入裸鼠背部皮下,8周后移植物组织学切片,HE染色观察及免疫组织化学检测DSP分布.结果：DPSC组移植物中可见新生基质,其相邻的结缔组织细胞部分出现极化,似成牙本质样细胞,局部放大可见类似于不典型的牙本质牙髓复合体.EMSC组有基质形成,结构不典型,有骨样基质形成,也存在有类牙本质牙髓复合体样结构.在移植后8周,DPSC组DSP在沉积的新生基质和部分出现极化的细胞胞浆中呈阳性表达.结论：通过免疫磁珠筛选的STRO＋-1的DPSC具有自我更新的特性,能够在体内继续分化形成牙本质样基质.EMSC组移植到裸鼠皮下,也能够形成基质.但是结构不典型.

Differentiation of dental pulp stem cell and ectomesenchymal stem cell implanted in nude mouse subcutaneous part

Objective：Dental pulp Stem Cell（DPSC） with immunomagnetic beads STRO＋-1 and ectomesenchymal Stem Cell（EMSC） were composite with ceramics bone.The differentiation ability of DPSC and EMSC was observed.Method：DPSC with immunomagnetic beads STRO＋-1 and EMSC were collected,which were composite with ceramics bone and implanted in nude mouse back subcutaneous part.The tissue of implantation was sliced up and dyed with HE.The distribution of DSP was determined whith immunohistochemistry.Result：In the DSPC implantation tissue,neo-substrate can be seen,polarization appeared in the adjoining tissue,the cells were like odontoblast-like cells,untypical dentin and pulp composition could be seen after zoomed out.In the EMSC implantation tissue,some untypical substrate could be seen.Bone-like substrate was formed and untypical dentin and pulp composition could also be seen.DSP was positively expressed in neo-substrate and partly polarizing cytoplasm of DPSC.Conclusion：SRTO＋-1 DPSC fitered by immunomagnetic beads has the characteristics of self regeration,and can differentiate to odontoblast-like substrate.EMSC can also produce substrate after implanted in nude mouse subcutaneous part,whose structure is untypical.