Abstract: A macromolecular compound with antitumor activity in which hydroxy groups in side chains of a polymer have the character of primary, secondary or tertiary alcohols and are completely or in part esterified with carboxyl in the position C4 of 1,2,4-tricarboxybenzene, whereas the carboxyls in positions C1 and C2 bind an atom of platinum with coordination bonded amino ligands.A method for producing the macromolecular compound consists in acylation of the polymer carrying alcohol groups with chloride anhydride of trimellitic acid of the formula II, ##STR1## hydrolyzing the anhydride in the subsequent step, and bonding an atom of bivalent platinum carrying an amino ligand to the formed vicinal carboxylic groups.

Abstract: The invention pertains to X-ray contrast spherical hydrogel particles based on polymers and copolymers of acrylates and methacrylates and to a method of their preparation.The subject of this invention are X-ray contrast spherical hydrogel particles based on polymers and copolymers of acrylates and methacrylates characterized by the particles of spherical form with diameter 0.2 to 2 mm, which strongly swell in water and contain a derivative of amino-triiodobenzoic acid of general formula I, ##STR1## where R.sup.1,R.sup.2 is hydrogen, acyl group with 1 to 3 carbon atoms or alkyl with 1 to 10 carbon atoms and X is halogen, --OH or --NH(CH.sub.2).sub.n NH.sub.2, where n=1-6, covalently bonded to the polymer skeleton.