ИСТИНА

Previously we obtained an amphiphilic polymer based on N-vinyl-2-pyrrolidone, modified by maleimide at the hydrophilic end of the polymer chain for further covalent conjugation with antitumor cytokine TRAIL DR5-B/V114C by the cysteine-maleimide bond. This method provides conjugation strictly by the N-end of the protein, ensuring the correct orientation of protein molecules on the surface of the nanoparticle. The polymer in concentration 1 mM was incubated overnight with TRAIL DR5-B/V114C protein with a 1:120 protein-to-polymer molar ratio in 150 mm NaCl solution, pH 7.5 at room temperature. The obtained nanoparticles were precipitated by centrifugation. The protein content was determined by Bradford assay. Polymer nanoparticles completely entrapped the protein from the solution, while the protein retained its solubility. The size of nanoparticles was investigated by dynamic light scattering. The average particle size was 1 μm. The obtained conjugates induced up to 40% cell death in colorectal carcinoma cell lines HT-29 and HCT116 in vitro. Thus, cytokine TRAIL DR5-B/V114C conjugated with polymer nanoparticles based on N-vinyl-2-pyrrolidone retained cytotoxicity similar to that of soluble cytokine TRAIL DR5-B/V114C. The work is supported by the RFBR grant No. 18-34-00812.