Previous studies have demonstrated the applicability of alpha-fetoprotein or its receptor-binding domain fused to the 6-histidine tag at the C-terminus (rAFP3D-His6) as vectors for targeted delivery of antitumor agents. The His6 tag is undesirable for further preclinical trials. Therefore, we designed a recombinant protein rAFP3D without any affine tags and assessed its functional activity. The protein was produced as inclusion bodies in Escherichia coli BL21 (DE3) cells. Optimal conditions for washing inclusion bodies and refolding the target protein were selected. We used a saturated (NH4)2SO4 solution at the primary purification stage to precipitate the main fraction of nontarget proteins. The second purification step included hydrophobic interaction chromatography using butyl-cellulose. The identity of the protein sequence was confirmed by tandem mass spectrometry. Circular dichroism demonstrated the authenticity of the secondary structure of the recombinant protein. MCF-7 tumor cells actively internalized fluorescently labeled rAFP3D. These results indicate that rAFP3D can be used for targeted drug delivery.

The paper describes the expression, purification and isolation of native sequence human alpha-fetoprotein recombinant receptor-binding domain and evaluation its functional activity for specific targeting to tumor cells.

New high-molecular-weight contrast agents based on polyamidoamine (PAMAM) dendrimers for targeted imaging of malignant tumors characterized by overexpression of human epidermal growth factor receptor (EGFR) and human alpha-fetoprotein receptor (RECAF) were designed. Conjugates of second (G2) and third (G3) generation polyamidoamine dendrimers with 1,4,7,10-tetraazocyclodecane-1,4,7,10-tetraacetic acid (DOTA) were obtained. The quantitative composition of the conjugates was determined by 1HNMR spectroscopy. It was shown that four out of the 16 terminal NH2 groups in G2-DOTA and nine out of the 32 groups in G3-DOTA were modified with DOTA. The morphology, size, and charge of the synthesized macromolecules were characterized by dynamic light scattering and electrophoresis. Gadolinium(III) was loaded into the conjugates and the Gd content was determined by atomic emission spectroscopy. For increasing the selectivity of accumulation in the tumor cells, two recombinant proteins able to bind selectively to EGFR and RECAF, namely, human recombinant epidermal growth factor (rEGF) and human recombinant 3rd domain of alpha-fetoprotein (3dAFPpG), were conjugated with G2 and G3 dendrimers. The conjugates containing vector molecules were mainly accumulated via clathrin-dependent endocytosis, whereas G2-DOTA and G3-DOTA were absorbed via caveolin-dependent endocytosis and macropinocytosis. The dendrimer conjugates with vector molecules were intensely accumulated in A549 cells characterized by high expression of EGFR (Herl) and RECAF, whereas the accumulation of conjugates in the control K562 cells (with low expression of Her1) and in the CD14− population of human unstimulated mononuclear white blood cells was insignificant. The 3dAFPpG-conjugated dendrimers were partly recycled. All synthesized conjugates had a rather low toxicity in the range of 350–450 µmol L−1 (IC50).

The polymeric form ofjosamycin was developed by loading of the antibiotic into spherical submicron particles made of poly(DL- lactide-co-glycolide) (PLGA 50/50) by double emulsion method. The average diameter and zeta-potential of particles synthesized were less than 150 nm and -35 mV respectively. Polymeric form showed antimicrobial activity against gram-positive, gram-negative, and atypical bacteria. The highest antibacterial activity compared to substance (more than 8-fold) was detected against Enterococcus faecalis. The results of in vivo studies of specific activity of drugs on the model of staphylococcal sepsis in mice showed an increase in the efficacy of the studied polymeric form by 1.5-fold compared with the josamycin substance.

Reactive oxygen species are generated by the redox reaction involving metalloporphyrin and ascorbic acid (AA) and lead to oxidative stress followed by cancer cell death. Polymer particles based on the copolymer of lactic and glycolic acid (PLGA) containing Fe III Cl-tetraphenylporphyrin (FeClTPP) were prepared and characterized. These particles in combination with AA exhibit cytotoxic activity against the K562 (human chronic myelogenous leukemia) and MCF7 (human breast adenocarcinoma) cell lines. Results in vitro indicated significant antitumor efficiency on mice inoculated with P388 leukemic cells and treated with FeClTPP/AA. The cytotoxic activity of the combined system is achieved due to the formation of reactive oxygen species. The application of this system to the study of anticancer efficiency in vivo on the model of mice that were hypodermically inoculated with P388 lymphocytic leukemia revealed a significant inhibition of tumor growth. The use of FeClTPP in combination with AA seems to be promising in cancer treatment.

Silybin (Slb) and ursodeoxycholic acid (UDCA) are hepatoprotectors used in the pathogenetic therapy of liver and biliary tract. However, low bioavailability of these drugs restricts their application. In order to solve this problem, Slb and UDCA were incorporated into polymer carriers based on polylactic acid and poly(lactic-co-glycolic acid) by nanoprecipitation. The polymeric forms obtained according to the developed and optimized method are nanoparticles with a size from 100 to 200 μm. In vitro experiments showed a 1.5–2-fold higher hepatoprotective activity of Slb- and UDCA-containing polymeric nanoparticles compared to free substances.

Polymer particles containing carboplatin (CPt) were developed by the inclusion of this antitumor agent in a copolymer of lactic and glycolic acids (PLGA-COOH 50/50). The polymer particles were found to have a spherical form with an average diameter not exceeding 200 nm, the ζ-potential is equal to–32.2±1 mV. The CPt-loaded polymer particles possess a cytotoxic activity against human small cell and non-small cell lung carcinoma (lines H69 and A549), as well as against mouse mammary adenocarcinoma (line Ca755). The results of the in vivo studies carried out on female mice of line C57Bl/6 with inoculated mouse melanoma of line B16 showed increasing of lifespan of the animals and inhibition of tumor growth for groups treated with the polymer particles, as compared to the animals treated with the drug substance CPt.

Разработан удобный метод региоселективного введения 1-β-D-галактопиранозилтимина в олигонуклеотиды. Изучены субстратные свойства модифицированных олигонуклеотидов в ферментативных реакциях образования и гидролиза межнуклеотидных связей.A convenient method of regioselective introduction of 1-β-D-galactopyranosylthymine into oligonucleotides was developed and the substrate properties of the modified oligonucleotides were investigated in the enzymic reaction of formation and hydrolysis of internucleotide bonds.

The easy synthesis of pyrimidine 5'-O-beta-D-ribofuranosyl nucleosides from 2',3'-di-O-acetylribonucleosides and 3'-O-tert-butyldiphenylsilyl-2'-deoxyribonucleosides is described. The stability upon O-glycosylation of various protecting groups is studied. The structure of the prepared disaccharide nucleosides is confirmed by NMR spectroscopy.

The synthesis of novel nucleotide analogues on the basis of ethylphosphonic acid was described. A rigid structural element, an amide or a double bond, was characteristics of the compounds synthesized. The antiviral and cytotoxic activities of these compounds were studied in cell cultures.

A simple synthesis of new cyclic nucleoside analogues with amide bond has been described, the structures being confirmed by NMR and UV spectroscopy. The obtained compounds have no anti-HIV, antiherpetic and cytotoxic activity.

A series of acyclic nucleosides and related alpha-phosphonyl acyclic analogues of dNTP with an amide bond have been prepared. Their antiviral and substrate properties were investigated.New acyclic nucleoside analogues with a rigid structural element, amide bond, have been synthesized in two stages. Alkylation of bis- trimethylsilylated thymine, cytosine and sodium salt of adenine by ethyl bromoacetate gave ethoxycarbonylmethyl derivatives ($) under bar 1a-c. Reaction of ($) under bar 1a-c with aminoalcohols afforded acyclic nucleosides ($) under bar 2-($) under bar 4 in good yields (Scheme 1), These analogues were found to be inactive against HIV-1 (CEM-SS cells) and HSV -1, HSV-2, HCMV, VZV (HFF cells) at concentrations up to 100 mu g/ml and were nontoxic towards CEM and HFF cells. However, it was shown that triphosphate of ($) under bar 2c is incorporated into the DNA chain by DNA polymerase from HSV-1(1). The absence of antiviral activity and cytotoxicity is probably due to the fact that ($) under bar 2-($) under bar 4 are not recognized by cellular and viral kinases.