ISSN:
0021-9304
Keywords:
gene therapy
;
immunoisolation
;
human growth hormone
;
β-glucuronidase
;
factor IX
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
,
Technology
Notes:
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 β-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. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 587-596, 1998.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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