| 摘要 |
A hydrogel comprising 1,2-diol or 1,3-diol groups acetalised with a radiopaque species, the radiopaque species comprising one or more covalently bound radiopaque halogens. Preferably the radiopaque species is acetalised in the form of a cyclic acetal. The hydrogel may comprise polyvinyl alcohol (PVA). The radiopaque species may be iodine or bromine, preferably iodinated or brominated phenyl groups. The hydrogel may be in the form of a microsphere or microparticle, preferably having a radiopacity of 500HU or greater. A further aspect of the invention is a composition comprising the hydrogel with a therapeutic agent absorbed into the hydrogel matrix. A method of making the radiopaque polymer comprising reacting a polymer comprising 1,2-diol or 1,3-diol groups with a radiopaque species capable of forming a cyclic acetal under acidic conditions. A method of making radiopaque hydrogel microspheres comprising swelling a pre-formed hydrogel microsphere with 1,2-diol or 1,3-diol groups in a solvent, mixing the swollen microsphere with a solution of radiopaque species capable of forming a cyclic acetal under acidic conditions and extracting the microspheres. A method of treatment wherein the hydrogel is administered into a blood vessel to embolise the blood vessel, preferably associated with a solid tumour. |
