Synthesis and properties of radiopaque polymer hydrogels: polyion complexes of copolymers of acrylamide derivatives having triiodophenyl and carboxylgroups and p-styrene sulfonate and polyallylamine

In order to pursue a possibility of application of radiopaque polymer hydro gels to vascular embolization, studies were done on synthesis of iodine-con taining copolyanions and properties of their hydrogels with polycation via formation of polyion complexes. Acrylamide derivatives having triiodophenyl and carboxyl groups were synthesized and copolymerized with sodium styrene sulfonate at various molar ratios of initiator to monomer and temperatures . Hydrogels were prepared by mixing aqueous solutions of the obtained radio paque copolyanions and polyallylamine. Embolization was examined by injecti on of these hydrogels into vein of a removed porcine kidney as a preliminar y test for transcatheter arterial embolization (TAE) for hepatocellular car cinoma. It was found that the hydrogels prepared from the copolycation obta ined under particular conditions give high X-ray contrasts of the vein and remained there, though copolycations with low molecular weights had a tende ncy to drain through the capillaries to the peripheral tissues. It is there fore concluded that the hydrogels examined in the present study are promisi ng for vascular embolization. (C) 2000 Elsevier Science B.V. All rights res erved.