Effect of capsule permeability on growth of CHO cells in Eudragit RL microcapsules: use of FITC-dextran as a marker of capsule quality.

Chinese hamster ovary fibroblast cells were encapsulated in Eudragit RL by interfacial precipitation. After encapsulation, they grew to fill the capsules, eventually growing outside the capsules as well. By encapsulating FITC-dextran (MW 150,000) along with the cells, it was possible to show that cell growth was faster in those capsules which lost fluorescence soon after encapsulation. These data were interpreted to signify that the intact Eudragit RL capsule membrane offered significant diffusion resistance to vital nutrients or particular metabolites, slowing or even preventing growth.