FIELD: chemistry.SUBSTANCE: invention relates to grafted polymer, imitating adhesive protein of mussel, to method of obtaining grafted polymer, to nanoparticles dispersed in water medium, colloid solution and contrast agent. Grafted polymer represents polyethyleneimine, grafted with polyethyleneglycol and polydihydroxyphenylalanine (PEI-graft-(PEG； PDOPA)). Polydihydroxyphenylalanine represents condensation polymer of 3,4-dihydroxyphenylalanine (DOPA). Method of obtaining grafted polymer includes several stages. At the first stage grafted copolymerisation of polyethyeleneglycol with polyethyleneamine is carried out. At the second stage after protection of hydroxyl groups of 3,4-dihydroxyphenylalanine synthesis of N-carboxyanhydride of 3,4-dihydroxyphenylalanine is performed in presence of triphosgene as catalyst. After that, reaction of polymer, obtained at the first stage, and N-carboxyanhydride of 3,4-dihydroxyphenylalanine in organic solvent is carried out. Colloid solution contains nanoparticles dispersed in water medium, with said grafted polymer being used as dispersion stabiliser. Contrast agent for magnetic-resonance tomography (MRT) includes said colloid solution.EFFECT: invention makes it possible to obtain biocompatible stabiliser, providing stable dispersion of nanoparticles in water medium, as well as to obtain highly effective nanoparticles as contrast agent for MRT.25 cl, 8 dwg, 2 tbl, 6 exИзобретение относится к привитому полимеру, имитирующему адгезивный белок мидии, к способу получения привитого полимера, к диспергированным в водной среде наночастицам, коллоидному раствору и контрастному агенту. Привитой полимер представляет собой полиэтиленимин, привитый полиэтиленгликолем и полидигидроксифенилаланином (PEI-graft-(PEG； PDOPA)). Полидигидроксифенилаланин представляет собой конденсационный полимер 3,4-дигидроксифенилаланина (DOPA). Способ получения привитого полимера включает несколько стадий. На первой стадии проводят привитую сополимеризацию по
