中文摘要：

目的：研究胞外基质（ECM）材料木糖葡聚糖（XG）对人肝癌细胞系HepG2细胞在细胞培养板上的贴壁性及对微囊化HepG2细胞的清蛋白合成速率、NH4＋清除速率、细胞增殖速率和间隙连接蛋白（Cx32）、细胞黏附分子（E-cadherin）表达的影响。方法：将HepG2细胞接种于不同浓度XG（0,0.5,1,4,6mg/ml）包被的细胞培养板上,孵育4h后收集贴壁细胞,BCA法测贴壁细胞总蛋白量进而测定细胞贴壁率;利用自制装置制备包被HepG细胞的海藻酸-多聚赖氨酸-海藻酸（APA）微囊并在培养微囊第6,10,14天以Human Serum Albumin Elisa Kit、Ammonia Assay Kit分别测定培养液中人血清白蛋白（HSA）和处理溶液中NH4＋的浓度,检测微囊化HepG2细胞的清蛋白合成速率和NH4＋清除速率;微囊培养1,2,3d后裂解微囊收集HepG2细胞并以RT-PCR方法检测细胞内Cx32和E-cadherin的表达情况。结果：HepG2细胞在XG包被的细胞培养板上的贴壁率随XG浓度增大呈递增趋势,同时微囊内细胞数随XG浓度增大、培养时间延长而增加,说明XG可促进细胞/基质间相互作用,促进细胞生长增殖;微囊化HepG2细胞的清蛋白合成速率与NH4＋清除速率在XG浓度为1 mg/ml时达到最大且较空白组高,说明XG对细胞合成及代谢功能有一定促进作用;加入XG的微囊内细胞表达Cx32、E-cadherin的时间较空白组提前,说明XG的存在促进了HepG2细胞肝脏特有功能的维持和体现。结论：XG对微囊化HepG2细胞的增殖及肝脏特有功能的体现都具有一定促进作用。

英文摘要：

Objective： To test the effects of xyloglucan （XG）, used as a new synthetic extracellular ma trix （ECM） for adhesion of HepG2 cells and the albumin secretion of micro capsule HepG2 cells, ammonia elimination, cell proliferation and Cx32, E-cadherin gene expression of encapsulated HepG2 cells. Methods： HepG2 cells were seeded on different concentrations of XG coated surface and incubated for 4 h, then the adherent cells were collected and quantified by BCA method for determining the adhesioin ratio. Micro capsules were prepared by self-made device and cultured for 6 d, 10 d or 14 d, then the Human Serum Albumin Elisa kit and Ammonia Assay Kit were applied to determine the sythetic rate of HSA and elimination rate of NH＋ , respectively. The expression of Cx32 and E-cadherin genes in capsulated HepG2 cells at separate days was detected by reverse transcriptase-polymerase chain reaction （RT-PCR）. Results： The adhesion ratio of HepG2 ceils onto coated surface gave a rising tendency and the cell number increased when the concentration of xyloglucan increased, indicating the promotion effects of xyloglucan on cell/matrix interactions and cell proliferation. The rates of albumin secretion and ammonia elimination were highest at t mg/ml of xyloglucan, and higher than that of blank groups, suggesting the promotion effects of xyloglucan on liver-specific functions of encapsulated HepG2 cells. The Cx32 and E-cadherin genes in alginate （AL）/XG capsules were more rapidly expressed, than in AL ones, respectively. Conclusion： Multicellular spheroid formation of HepG2 cells can enhance the liver-specific functions in the three-dimensional space in the presence of XG as a new synthetic ECM.