Metal-Polymer Complexes as Antibacterial Agents: Characterization and Antibacterial Activity of Metal-Polymer Nanocomposite Based on Copolymers of Polyethylene(Propylene)Glycolmaleates with Acrylic Acid

The article presents the results of the synthesis and study of the structure of metal-polymer complexes p-EGM: АА/Ag, p-EGM: АА/Ni, p-EGM:АА/Ag-Ni, p-PGM:АА/Ag, p-PGM:АА/Ni, p-PGM:АА/Ag-Ni based on copolymers of polyethylene(propylene)glycolmaleates with acrylic acid and metals, which have been characterized using microscopy, spectroscopy and thermogravimetry. The antimicrobial activity of a new metal-polymer nanocomposite p-PGM/АА-Ag was studied, which is showing high efficiency against standard strains of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus.

Direct Comparison of Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes Targeting STAT3 in a Syngeneic Murine Model of TNBC

RNA interference (RNAi) molecules have tremendous potential for cancer therapy but are limited by insufficient potency after intravenous (IV) administration. We previously found that polymer complexes (polyplexes) formed between 3′-cholesterol-modified siRNA (Chol-siRNA) or DsiRNA (Chol-DsiRNA) and the cationic diblock copolymer PLL[30]-PEG[5K] greatly increase RNAi potency against stably expressed LUC mRNA in primary syngeneic murine breast tumors after daily IV dosing. Chol-DsiRNA polyplexes, however, maintain LUC mRNA suppression for ~48 h longer after the final dose than Chol-siRNA polyplexes, which suggests that they are the better candidate formulation. Here, we directly compared the activities of Chol-siRNA polyplexes and Chol-DsiRNA polyplexes in primary murine 4T1 breast tumors against STAT3, a therapeutically relevant target gene that is overexpressed in many solid tumors, including breast cancer. We found that Chol-siSTAT3 polyplexes suppressed STAT3 mRNA in 4T1 tumors with similar potency (half-maximal ED50 0.3 mg/kg) and kinetics (over 96 h) as Chol-DsiSTAT3 polyplexes, but with slightly lower activity against total Stat3 protein (29% vs. 42% suppression) and tumor growth (11.5% vs. 8.6% rate-based T/C ratio) after repeated IV administration of equimolar, tumor-saturating doses every other day. Thus, both Chol-siRNA polyplexes and Chol-DsiRNA polyplexes may be suitable clinical candidates for the RNAi therapy of breast cancer and other solid tumors.

Titration of weak base fibrous anion exchangers in the presence of complex-forming divalent cations

Curves of potentiometric titration of fully protonized fibrous ion exchangers with potassium hydroxide against the background of 1 M KCl in the presence of chlorides of Ni2+, Со2+, Сu2+ and Ca2+ were obtained. The ion exchangers were synthesized by modifying of industrial polyacrylonitrile fiber with diethylenetriamine and triethylenetetraamine and predominantly contained functional groups R-CO-NH- (CH2CH2NH)nH (n = 2 or 3) and a small amount of carboxyl groups. The sorption of Ni2+, Со2+, Сu2+ и Ca2+by ion exchangers was calculated from the data obtained depending on the pH of the medium. It was found that the investigated ion exchangers with high selectivity sorb heavy metal ions in a wide range of acidity of solutions (pH 2–9) due to the formation of metal-polymer complexes with polyamine functional groups. The maximum sorption capacity is 1.5–2.7 and 4–5 meq/g for ion exchangers with n = 2 and 3, respectively.

Novel Polymeric Metal Complexes for Dye Sensitizer : Synthesis and Photovoltaic Performances

Four novel polymeric metal complexes with a D-A-π-A motif, BDTT-PY-Cd, BDTT-PY-Zn, BDTT-PY-Cu and BDTT-PY-Ni, were designed, synthesized and characterized. These polymeric metal complexes were made up with Cd(Ⅱ), Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ) complexes, thienylbenzo-[1,2-b:4,5-b'] dithiophene (BDTT) and the 8-quinolinol derivative, which were used severally as dye sensitzers’ auxiliary electron acceptors (A), electron donor (D) and π bridges as well as the acceptors (A). Under AM 1.5 irradiation (100 mW cm-2), the devices of dye sensitized solar cells (DSSC) based on four polymer complexes exhibited short-circuit photocurrent densities (Jsc) of 17.45 mA cm-2, 14.75 mA cm-2, 13.94 mA cm-2, and 12.00 mA cm-2, as well as attractive power conversion efficiencies (PCE) of were 9.73 %, 8.02 %, 6.82 % and 6.12 %, respectively. The photovoltaic conversion efficiency (PCE) and short-circuit photocurrent density (Jsc) of BDTT-PY-Cd, BDTT-PY-Zn, BDTT-PY-Cu and BDTT-PY-Ni decrease in order because the radius and charge number of the metal ion affect the strength of the coordination bond between the metal ion and the ligand. These results provides a new way of development for efficient and stable dye sensitizers in the future.

Isomeric bis(pyrazolyl)sulfones based on bis(1,1-dihydropolyfluoroalkyl)sulfones. A new type of ligands for metal-polymer complexes with silver cation

The work is devoted to the methods of synthesis of bis(polyfluoroalkenyl)sulfones and bis(polyfluoromethoxyalkenyl)sulfones as well as to the study of their reactions with diazomethane, resulting in the formation of N-methylated bis(pyrazolyl)sulfones isomers. Methods for the preparation of bis(polyfluoromethoxyalkenyl)sulfones not described previously in the literature have been developed by the addition of triethylamine and trimethylchlorosilane to a solution of the respective bis(polyfluoroalkyl)sulfones and methanol in diethyl ether in an argon atmosphere. A new method for the preparation of a previously unknown bis(3,3-difluoro-2,2-dimethoxypropyl)sulfone was suggested. The reaction occurs at room temperature in methanol in the presence of lithium hydroxide monohydrate. It was found that different regioisomeric bis(polyfluoroalkylpyrazolyl)sulfones are formed when using different methoxy derivatives of bis(polyfluoroalkenyl)sulfones in reaction with diazomethane, depending on the length of the polyfluoroalkyl moiety. These experimental data suggest that the attack of the double bond of methoxy-derived bis(polyfluoroalkenyl)sulfones by a molecule of diazomethane is influenced not only by the presence of an alkoxyl group, but also by the length of the polyfluoroalkyl substituent. The obtained bis(pyrazolyl)sulfones were investigated for the possibility of their use as ligands in the chemistry of metal complexes. It was shown that 5,5'-sulfonylbis[4-(difluoromethyl)-1-methyl-1H-pyrazole] forms a polymeric metal complex with silver nitrate. The results of X-ray structural analysis of the prepared coordination compound are presented. According to these results, the silver atom coordinates with two nitrogen atoms of pyrazole cycles of different molecules in the crystal of the obtained metal-complex compound, forming a supramolecular structure. In our opinion, an important role in this arrangement is played by the nitrate group that is coordinated with two silver atoms. As a result, we observed a supramolecular structure in the crystal that had a spiral structure with some free space in the middle. The paper also presents the results of spectral and X-ray diffraction analysis of a new regioisomeric compound of bis(3-hexafluoropropyl-1-methylpyrazolyl)sulfone.

Direct Comparison of Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes Targeting STAT3 in a Syngeneic Murine Model of TNBC

RNA interference (RNAi) molecules have tremendous potential for cancer therapy but are limited by insufficient potency after i.v. administration. We previously found that polymer complexes (polyplexes) formed between 3’-cholesterol-modified siRNA (Chol-siRNA) or DsiRNA (Chol-DsiRNA) and the cationic diblock copolymer PLL[30]-PEG[5K] greatly increase RNAi potency against stably expressed LUC mRNA in primary syngeneic murine breast tumors after daily i.v. dosing. Chol-DsiRNA Polyplexes, however, maintain LUC mRNA suppression ~48 h longer after the final dose than Chol-siRNA Polyplexes, suggesting they are a better candidate formulation. Here, we directly compared the activities of Chol-siRNA and Chol-DsiRNA Polyplexes in primary murine 4T1 breast tumors against STAT3, a therapeutically relevant target gene overexpressed in many solid tumors including breast cancer. We found that Chol-siSTAT3 Polyplexes suppressed STAT3 mRNA in 4T1 tumors with similar potency (half-maximal ED50 0.3 mg/kg) and kinetics over 96 hours as Chol-DsiSTAT3 Polyplexes but with slightly lower activity against total Stat3 protein (29% vs. 42% suppression) and tumor growth (11.5% vs. 8.6% rate-based T/C ratio) after repeated i.v. administration of tumor-saturating doses every other day. Thus, both Chol-siRNA Polyplexes and Chol-DsiRNA Polyplexes may be suitable clinical candidates for RNAi therapy of breast cancer and other solid tumors.

Comparison of Optical Ammonia-Sensing Properties of Conducting Polymer Complexes with Polysulfonic Acids

Thin films of conducting polymer complexes with polysulfonic acids of various structures were electrochemically deposited onto transparent FTO electrodes. The behavior of the polymer-based optical ammonia vapor sensors in response to various concentrations of ammonia vapors, ranging from 5 to 135 ppm, was investigated, including the response time and response amplitude. It was found that the nature of the conducting polymers (poly (3,4-ethylenedioxythiophene), polypyrrole, polyaniline), as well as the structure of the polyacids, affected the sensing performance of the obtained complexes.