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OwnerSmadar Cohen, Carmen Bano +4inventors
InventorsSmadar Cohen, Carmen Bano, Karyn B. Visscher, Marie B. Chow, Harry R. Allcock, Robert S. Langer
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A method for encapsulating biologically-labile materials such as proteins, liposomes, bacteria and eucaryotic cells within a synthetic polymeric capsule, and the product thereof, are disclosed. The method is based on the use of a water-soluble polymer with charged side chains that are crosslinked with multivalent ions of the opposite charge to form a gel encapsulating biological material, that is optionally further stabilized by interactions with multivalent polyions of the same charge as those used to form the gel. In the preferred embodiment, hydrolytically stable polyphosphazenes are formed of monomers having carboxylic acid side groups that are crosslinked by divalent or trivalent cations such as Ca.sup.2+ or Al.sup.3+, then stabilized with a polycation such as poly-L-lysine. A variety of different compositions can be formed from the crosslinked polymer. In a preferred embodiment, microcapsules are made by spraying an aqueous solution of polyphosphazene and material to be encapsulated into a calcium chloride solution. A semi-permeable membrane is formed on the microspheres by complexation of the surface carboxylate groups with poly(L-lysine).
A composition prepared from an ionically crosslinkable synthetic polymer that is soluble in an aqueous solution prior to crosslinking and has charged side groups which are crosslinked by reaction of the side groups with multivalent ions of the opposite charge to form a gel, followed by reaction of the side groups with multivalent polyions of the opposite charge to form a semi-permeable membrane,
A method for synthesizing a synthetic polymeric crosslinked material comprising:
Dependencies are inferred from the claim text.