Towards the preparation of a MMA-PEO block copolymer for the microencapsulation of mammalian cells.

Polymethyl methacrylate-polyethylene glycol-polymethyl methacrylate triblock copolymers (PMMA-PEO-PMMA) were synthesized by reductive amination coupling of preformed aldehyde-terminated PEO and amine-terminated PMMA. These were intended for use as high water content and therefore high permeability, biocompatible encapsulating materials for mammalian cells. Evidence for the formation of the block copolymer was obtained indirectly from precipitation experiments and IR analysis of the water-soluble extract of the polymer. Unfortunately the pure copolymer could not be separated from the homopolymers, because of the difficulty in finding appropriate non-solvents and the apparently limited yield of the product. Further work is necessary to confirm the underlying hypothesis of this work, i.e. that such a block copolymer would have a high permeability to the small proteins critical to microencapsulated cell survival or function.