Chemosensitivity test using immunoprotected culture system in vivo.

葡萄糖等低分子物质可以通过聚赖氨酸和海藻酸盐组成的膜，而免疫球蛋白等高分子物质不能通过该膜。因此，活细胞微囊化可以保护异种移植细胞免受排斥反应。本研究旨在建立一种新的微囊化人癌细胞移植到小鼠体内的化疗敏感性检测系统。1.细胞包囊：微囊化是按照Lin最初报道的方法，以Ishikawa细胞(已建立的子宫内膜腺癌细胞系)为囊化细胞制备而成。细胞悬浮在浓度为1×106/ml的海藻酸钠中，经包被多聚赖氨酸后雾化成凝胶状球状微滴，再用海藻酸钠和CaCl2洗涤。用柠檬酸钠进一步洗涤，使胶囊内的凝胶液化。微囊的体外培养将微囊悬浮于培养基中，在密闭条件下进行培养。相差显微镜观察发现，早期的孤立癌细胞生长迅速，微囊内可形成泡沫聚集体。SDI法检测包埋细胞生长曲线显示细胞呈指数生长。

Low molecular weight substances such as glucose can pass through the membrane composed of polylysine and alginate, but the high molecular weight substances such as immunoglobulin can not pass through this membrane. Therefore, microencapsulation of living cells can protect heterotransplanted cells from rejection. This research aims to establish a new chemosensitivity test system using microencapsulated human cancer cells transplanted into mouse in vivo.1.Cell encapsulationThe microcapsules were produced according to the procedure originally reported by Lin, using the Ishikawa cells (an established endometrial adenocarcinoma cell line) for encapsulated cells. Cells were suspended in sodium alginate at a concentration of 1x10^6/ml. This cell suspension formed gelled spherical microdroplets by atomizing into CaCl_2 After coated with polylysine, the gels were washed with sodium alginate and CaCl_2 again. Further washing was employed with sodium citrate to liquify the gel inside the capsules. The adequate size of the capsules with a membrane of polylysine sandwiched between 2 layrs of alginate were 0.5 mm in diameter for manipulation.After several trials and errors, the microcapsules could be produced smoothly.2.Cultivation of the microcapsules in vitroThe capsules were suspended in the culture media and cultured under the closed condition.The phasecontrast microscopic findings revealed that the solitary cancer cells in its early stage grow rapidly foaming aggregates in the microcapsules. The growth curves of the encapsulated cells assessed by SDI analysis showed exponential growth of the cells.