Wikström Jonna, Elomaa Matti, Syväjärvi Heli, Kuokkanen Johanna, Yliperttula Marjo, Honkakoski Paavo, Urtti Arto
Drug Discovery and Development Technology Center, University of Helsinki, P.O. Box 56, Helsinki 00014, Finland
Biomaterials. 2008 Mar;29(7):869-76. doi: 10.1016/j.biomaterials.2007.10.056. Epub 2007 Nov 28.
The goals of this study were to evaluate human retinal pigment epithelial cell line (ARPE-19) for cell encapsulation and to optimize the alginate-based microencapsulation. We used immortalized ARPE-19 cells and the transfected sub-line that expresses secreted alkaline phosphatase (SEAP) reporter enzyme. Alginate was cross-linked with different divalent cations (Ca(2+), Ba(2+), Sr(2+) and combination of Ca(2+) and Ba(2+)), coated first with poly-l-lysine (PLL), and then with alginate. Microcapsules with different pore sizes and stability were generated. The pore size of the microcapsules was assessed by the release of encapsulated fluorescein isothiocyanate (FITC)-dextrans. The viability of the cells in the microcapsules was studied in vitro by assessing the secretion rates of SEAP and oxygen consumption by the cells. The best microcapsule morphology, durability and cellular viability were obtained with alginate microcapsules that were cross-linked with Ca(2+) and Ba(2+) ions and then coated with PLL and alginate. Based on FITC-dextran release these microcapsules have porous wall that enables the rapid contents release. The ARPE-19 cells maintained viability in the Ca(2+) and Ba(2+) cross-linked microcapsules for at least 110 days. The alginate microcapsules cross-linked with Ca(2+) and Ba(2+) have sufficiently large pore size for prolonged cell viability and for the release of secreted SEAP model protein (Mw 50 kDa; radius of gyration of 3 nm). ARPE-19 cells show long-term viability and protein secretion within alginate microcapsules cross-linked with Ca(2+) and Ba(2+). This combination may be useful in cell therapy.
本研究的目的是评估人视网膜色素上皮细胞系（ARPE-19）用于细胞包封，并优化基于海藻酸钠的微囊化。我们使用了永生化的ARPE-19细胞和表达分泌性碱性磷酸酶（SEAP）报告酶的转染亚系。海藻酸钠与不同的二价阳离子（Ca(2+)、Ba(2+)、Sr(2+)以及Ca(2+)和Ba(2+)的组合）交联，首先用聚-L-赖氨酸（PLL）包被，然后再用海藻酸钠包被。生成了具有不同孔径和稳定性的微胶囊。通过包封的异硫氰酸荧光素（FITC）-葡聚糖的释放来评估微胶囊的孔径。通过评估细胞分泌SEAP的速率和细胞的耗氧量，在体外研究微胶囊中细胞的活力。用与Ca(2+)和Ba(2+)离子交联、然后用PLL和海藻酸钠包被的海藻酸钠微胶囊获得了最佳的微胶囊形态、耐久性和细胞活力。基于FITC-葡聚糖的释放，这些微胶囊具有多孔壁，能够实现内容物的快速释放。ARPE-19细胞在Ca(2+)和Ba(2+)交联的微胶囊中保持活力至少110天。与Ca(2+)和Ba(2+)交联的海藻酸钠微胶囊具有足够大的孔径，以实现细胞的长期存活和分泌的SEAP模型蛋白（分子量50 kDa；回转半径3 nm）的释放。ARPE-19细胞在与Ca(2+)和Ba(2+)交联的海藻酸钠微胶囊中显示出长期活力和蛋白质分泌。这种组合可能在细胞治疗中有用。
