Peirone M, Ross C J, Hortelano G, Brash J L, Chang P L
Department of Biology, McMaster University, Hamilton, Ontario, Canada.
J Biomed Mater Res. 1998 Dec 15;42(4):587-96. doi: 10.1002/(sici)1097-4636(19981215)42:4<587::aid-jbm15>3.0.co;2-x.
Microencapsulation of recombinant "universal" cells with immunoprotective membranes is an alternate approach to somatic gene therapy. Therapeutic gene products secreted by these cells can be delivered to different patients without immunosuppression or genetic modification of the host's cells. The encapsulation of different mammalian cell types (epithelial cells, fibroblasts, and myoblasts) is compared among three alginate-based microcapsules: (1) calcium-linked alginate microcapsules with a solubilized core and a poly-L-lysine-alginate-laminated surface; (2) barium-linked alginate beads with a gelled core; and (3) a hybrid formulation of barium-linked alginate beads with a poly-L-lysine-alginate-laminated surface. The mechanical stability of the different microcapsule types, as measured with a cone-and-plate shearing apparatus, was superior in the two barium-linked alginate beads. All cell types maintained high viability (65-90%) in culture after encapsulation. The recombinant gene products secreted by these cells (human growth hormone MW = 22,000, human factor IX MW = 57,000, and murine beta-glucuronidase MW = 300,000) were able to traverse the three microcapsule types at similar rates. Cell numbers within the microcapsules increased twofold to > 20-fold over 4 weeks, depending on the cell type. Epithelial and myoblast cell numbers were not affected by microcapsule formulation; however, fibroblasts proliferated the most in the calcium-linked alginate spheres. These results show that for culturing fibroblasts in a mechanically stable environment the classical calcium-linked microcapsules are adequate. However, where mechanical stability is a more critical requirement, the solid barium-linked gelled beads are more appropriate choices.
用免疫保护膜对重组“通用”细胞进行微囊化是体细胞基因治疗的一种替代方法。这些细胞分泌的治疗性基因产物可以在不进行免疫抑制或宿主细胞基因改造的情况下递送至不同患者。比较了三种基于藻酸盐的微囊对不同哺乳动物细胞类型（上皮细胞、成纤维细胞和平滑肌细胞）的包封情况：（1）具有可溶解核心和聚-L-赖氨酸-藻酸盐层状表面的钙连接藻酸盐微囊；（2）具有凝胶化核心的钡连接藻酸盐珠；（3）具有聚-L-赖氨酸-藻酸盐层状表面的钡连接藻酸盐珠的混合制剂。用锥板剪切仪测量，两种钡连接藻酸盐珠的不同微囊类型的机械稳定性更佳。所有细胞类型在包封后在培养中均保持高活力（65-90%）。这些细胞分泌的重组基因产物（人生长激素分子量=22,000，人因子IX分子量=57,000，小鼠β-葡萄糖醛酸酶分子量=300,000）能够以相似的速率穿过三种微囊类型。微囊内的细胞数量在4周内增加了两倍至>20倍，具体取决于细胞类型。上皮细胞和平滑肌细胞的数量不受微囊制剂的影响；然而，成纤维细胞在钙连接藻酸盐球中增殖最多。这些结果表明，对于在机械稳定的环境中培养成纤维细胞，经典的钙连接微囊就足够了。然而，在机械稳定性是更关键要求的情况下，固态钡连接凝胶珠是更合适的选择。
