A new process for embedding cells in agarose is described. Beads were obtained by extruding an ultralow gelling temperature agarose solution in a capillary containing a hydrophobic medium flowthrough. The toxicity of the procedure has been evaluated by monitoring the energy status of agarose-embedded C6 glioma cells with 31 P nuclear magnetic resonance (NMR). Suspension and microbead cultures of hybridoma cell line were compared. In suspension culture the number of cells and the antibody concentrations increased for 5 days before the stationary phase began, when the cultures were stopped. In agarose bead cultures, the gel provided an enormous support surface area (50 m2/ mL of gel). It was possible to seed 20-fold more cells. The gel pressure modified the proliferative process and antibody pattern secretion. In particular, the antibodies could be harvested for two weeks.

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ABSTRACT:A new process for microencapsulating cells is described. Cells in solution in agarose were extruded from a syringe into a paraffin oil containing medium. Solid microspheres were produced when the agarose gelled. A rigid interface around each bead was produced by polymerization of a latex seeded solution of a mixture of 5% acrylamide and 0.25% bisacrylamide. Cell viability was demonstrated by radioimmunoassay of prolactin liberated from encapsulated pituitary cells.

Microencapsulation of adrenal cells is proposed for reducing the nonspecific inflammatory reaction observed around polymer implants. This hypothesis was tested by comparing both host cellular reaction and the surrounding graft cell populations which appeared either when agarose embedded cells or when empty agarose beads were implanted. Our results showed that the fibrotic material that surrounded the implanted empty agarose microbeads was not as severe and important when adrenal cells were present. Similarly, T lymphocyte population surrounding the graft was considerably reduced together with the percentage of CD4 and CD8 positive cell subpopulations. The activation macrophage marker IaD disappeared. Our results support the hypothesis that embedded adrenal cells may be a suitable solution for reducing early inflammatory events due to microcapsules implantation.