Amphiphilic copolymers of N-vinylpyrrolidone with (di)methacrylates as promising carriers for the platinum(IV) complex with antitumor activity

Abstract

Water-soluble polymer compositions of the lipophilic complex of cis -bis[(nitroxyethyl)-isonicotinamide- N ]-tetrachloroplatinum( iv ) with antitumor activity were prepared. The complex was solubilized by amphiphilic copolymers of N -vinylpyrrolidone (VP) with (di)methacrylates synthesized by radical copolymerization in toluene in the absence of any inhibitors of polymer chain growth. Aqueous buffer solutions of the nanostructures were studied by dynamic light scattering, and the influence of the concentrations of the complex and copolymer and temperature on the nanoparticle size (hydrodynamic radius) was estimated. The nanostructures based on the VP copolymer with triethylene glycol dimethacrylate are shown to be thermosensitive and decompose when the temperature rises to physiologically significant values. According to the TEM data, the polymer particles are spherical and contain inclusions of the Pt IV complex ∼4 nm in size. The polymer compositions were studied using CV, TGA, and DSC methods. The results of IR spectroscopic analysis of the polymer compositions and quantum chemical modeling indicate the formation of the hydrogen bond between the NH groups of the complex and VP copolymer.