摘要
目的：海藻酸钠多聚赖氨酸海藻酸钠（ＡＰＡ）微囊能够成功地延长同种或异种移植组织或细胞的存活时间，而微囊膜的通透性是决定囊内细胞存活和微囊免疫隔离效果的关键因素。本实验用激光扫描共聚焦显微镜（ＬＳＣＭ）以测定ＡＰＡ微囊膜的通透性。方法：采用ＦＩＴＣ标记的不同分子量的葡聚糖（ＦＤ）和ＩｇＧ与微囊共孵育，观察形成的激光共聚焦图像。结果：平均分子量为７１和１６７ｋＤａ的ＦＤ及分子量为１５０ｋＤａ的ＩｇＧ均不能扩散进入微囊内，而平均分子量为１２和２０ｋＤａ的ＦＤ则可自由扩散进微囊内，平均分子量为４０ｋＤａ的ＦＤ可部分扩散进微囊内。提示微囊膜的截割分子量在４０～７１ｋＤａ之间。利用ＬＳＣＭ的时间扫描功能可动态观察ＦＤ１２向单个微囊内的扩散情况，表明较小直径微囊内ＦＤ１２增加的速度明显快于直径较大的微囊。包囊细胞和含血清的培养液对微囊膜的分子截割范围和ＦＤ１２向微囊内的扩散速度无明显影响。结论：我们制备的ＡＰＡ微囊既可允许小分子的营养物通过，以满足微囊内细胞的生存需要，又能截割７１ｋＤａ以上的大分子物质，起到免疫隔离作用。
Objective:Alginate polylysine alginate (APA) microcapsules could successfully prolong the survival of homotransplanted or xenotransplanted tissues or cells. The permeability of microcapsule membrane is the main determinant factor for the survival of encapsulated cells and the function of immunoisolation. This article was designed to determine the permeability of APA microcapsule by using laser scanning confocal microscope (LSCM).Methods:After incubating with FITC labeled dextran (FD)or IgG, the APA microcapsules were observed by LSCM.Results:FITC dextran with MW 71 and 167 kDa, and FITC IgG with MW 150 kDa could not diffuse into the capsules. FITC dextran with MW 12 and 20 kDa diffused into the capsules freely. FITC dextran with MW 40 kDa could partly diffuse into the capsules.So the molecular cut off value of the microcapsule world be 40～71 kDa. Using the function of scanning with time of the LSCM, the diffusion process of FD 12 into the capsules was observed dynamically. It was showed that the increasing of FD 12 in the capsules with smaller diameter was faster than the larger capsules. In addition, it was proved that microencapsu lated cellsand serum containing culture medium did not affect the molecular cut off range of the microcapsule and the diffusion velocity of FD 12 into the capsules. Conclusions: APA microcapsule prepared by us may cut off the substances with molecular weight beyond 71kDa to perform immunoisolating function and be permeable to nutrients with low molecular weight for the survival of encapsulated cells.Determination of the permeability of microcapsule using laser scanning confocal microscopy is simple and convenient, being able to know property of microcapsule within a short time.
出处
《中国体视学与图像分析》
1999年第1期16-19,24,共5页
Chinese Journal of Stereology and Image Analysis
基金
国家自然科学基金
