小鼠骨髓间充质干细胞外泌体的分离与鉴定

目的探讨骨髓间充质干细胞的外泌体的分离与鉴定方法。方法通过全骨髓贴壁法培养间充质干细胞;用新兴试剂法收集外泌体,采用电镜、粒径检测、流式细胞仪和Western blot鉴定外泌体。结果第三代骨髓间充质干细胞表面CD45呈阴性表达,CD73和CD105呈阳性表达;骨髓间充质干细胞外泌体呈圆形或椭圆形,大小不均匀,直径30~100 nm,有完整的膜结构;粒径检测显示颗粒直径主峰为61.25 nm,直径为20~200 nm的颗粒占72.4%;外泌体CD63和CD81呈阳性表达;细胞培养上清液中可检测到外泌体CD9和CD63的蛋白表达。结论在培养间充质干细胞的培养基中可以收集到外泌体,可以通过透射电镜、粒径检测、流式细胞仪和Western blot对骨髓间充质干细胞的外泌体进行鉴定。

Structure Design and Finite Element Analysis of a Connection Assembly Program

The new connection assembly program contains four cone-shapes of fixed welders and four bolts.It is used for connecting the cover assembly of a Down-The-Hole( DTH) drill rig and its chassis.The design feasibility and reliability are evaluated according to the mechanical calculation and finite element method.