MICROCAPSULES FOR CELL ENTRAPMENT BY TEMPLATE POLYMERIZATION OF A SYNTHETIC HYDROGEL COATING AROUND CALCIUM ALGINATE GEL - PRELIMINARY DEVELOPMENT

Stable, water-soluble copolymers of glycidyl methacrylate with n-vinyl pyrrolidinone (I) were, prepared by free-radical polymerization. Water-soluble copolymers of 2-hydroxyethyl methacrylate with methacrylic acid (II) were examined as co-reactants with (I) to form hydrogel matrices. Upon mixing of (I) and (II) in solution, a covalently crosslinked hydrogel was formed, presumably by etherification of epoxy functionality on (I) with hydroxyls on (II). Synthetic hydrogel-coated gel beads were prepared from an aqueous mixture of sodium alginate and (II) by treatment with solution containing (I) and calcium ion. An elastic, defect free and indefinitely stable covalently crosslinked hydrogel coating was formed around the calcium alginate by surface reaction of (I) and (II). Encapsulated guinea-pig red blood cells suffered minimal lysis over a 4 day period due to isolation and protection from the reacting species by the interior alginate gel matrix.