Modification of multiwalled carbon nanotubes with a ruthenium drug candidate-indazolium[tetrachlorobis(1H-indazole)ruthenate(III)] (KP1019 ).

Functionalized carbon nanotubes are interesting, promising and unique delivery systems for anticancer drugs, which are now in the spotlight of nanomedicine. Connecting nanotubes with anticancer drugs or new compounds with anticancer properties aims at improving their stability, efficiency and reduces the toxic side effects of cancer treatment. In our research, we are interested in connecting functionalized MWCNTs-NH2 with [InH][trans-RuCl4(In)2], (KP1019) which is one of the most promising anticancer ruthenium(iii) drug candidates, known mainly as a cytotoxic agent for the treatment of platinum-resistant colorectal cancers. As a result of the amidation of MWCNTs (1), MWCNTs-NH2 (2) were obtained. Then, they were modified with [InH][RuCl4(In)2] (4) and the nanosystem [MWCNT-NH3+][RuCl4(In)2-] (3) was obtained. The characterization of the resulting products was performed using IR, Raman spectroscopy, thermal gravimetric, XRD, STEM-EDX, ESI-MS, ICP-MS, and XPS analyses. The cytotoxic activity has been tested on human lung carcinoma (A549), chronic myelogenous leukemia (K562) and human cervix carcinoma (HeLa) cells which showed the higher toxicity of the nanosystem than the ruthenium complex.

Synthesis, X-ray structure, physicochemical properties and anticancer activity of mer and fac Ru(iii) triphenylphosphine complexes with a benzothiazole derivative as a co-ligand.

Two mononuclear ruthenium(iii) mer- and fac-isomers of the formula [RuCl3(PPh3)(dmpbt)] (where PPh3 = triphenylphosphine, dmpbt = 2-(3,5-dimethylpyrazoll-yl)benzothiazole) have been synthesised from the reaction of [RuCl3(PPh3)3] with a bidentate ligand - dmpbt. Appropriate reaction conditions allowed obtaining the two isomers separately without separation techniques. X-ray crystallography has determined the crystal and molecular structures of the new complexes. mer-Ru(iii) (1) crystallised in the monoclinic P2(1)/n group, and fac-Ru(iii) (2, 2') in the triclinic P1[combining macron] space group. The composition of the ruthenium coordination sphere was confirmed and characterised using spectroscopic techniques (FT-IR, UV-vis and EPR), elemental analysis and mass spectrometry (MS-FAB). The structures of the complexes obtained were analysed using X-ray and other spectroscopic methods (IR and UV-vis). The electrochemical properties of the ligand and the complex compound were identified using cyclic voltammetry, determining the potential and charge of faradaic processes. Both isomers are redox active and display quasi-reversible metal centered redox processes for the Ru(iii)/Ru(ii) pair. Moreover, preliminary tests of their biological activity were performed. The cytotoxicity of these compounds has been tested for human lung carcinoma (A549), chronic myelogenous leukemia (K562), human cervix carcinoma (HeLa) cells, acute lymphoblastic leukemia (MOLT-4), human breast adenocarcinoma cell line (MCF-7) and normal human umbilical vein endothelial cells (HUVEC). The ability to induce apoptosis has been demonstrated in caspase 3/7 activity assay. In addition, the lipophilicity of both isomers was described by a partition coefficient, log P, values of which were estimated by the shake-flask method. The interesting and promising preliminary results of the biological and chemical activities of the new octahedral mer/fac Ru(iii) complexes motivate further in vitro and in vivo studies.

The fungicidal properties of the carbon materials obtained from chitin and chitosan promoted by copper salts.

Renewable raw materials chitin and chitosan (N-deacetylated derivative of chitin) were subjected to action of different copper modifiers that were carbonized in the atmosphere of the N2 inert gas. As a result of the novel manufacturing procedure, a series of carbon materials was obtained with developed surface area and containing copper derivatives of differentiated form, size, and dispersion. The copper modifier and manufacturing procedure (concentration, carbonization temperature) influence the physical-chemical and fungicide properties of the carbons. The received carbons were chemically characterized using several methods like low-temperature adsorption of nitrogen, X-ray diffraction analysis, scanning electron microscopy, cyclic voltammetry, elemental analysis, and bioassay. Besides chemical testing, some biological tests were performed and let to select carbons with the highest fungicidal activity. Such carbons were characteristic of the specific form of copper derivatives occurring in them, i.e., nanocrystallites of Cu(0) and/or Cu2O of high dispersion on the surface of carbon. The carbons may find an application as effective contact fungistatic agents in cosmetology, medicine, food industry, etc.

Study of charge distribution on the surface of biocolloids.

Potentiometric titration and zeta potential measurements are crucial techniques for the characterization of the surface properties of bacterial cells. In this study, we investigated the effects of two commonly used electrolytes, NaNO(3) and NaClO(4), on the viability and acid-base properties of Gram-positive bacteria Bacillus subtilis. B. subtilis are non-pathogenic bacteria which are often used to model the surface properties of pathogenic microorganisms of the same genus, including Bacillus anthracis and Bacillus cereus. The survival rates of bacterial cells treated with NaNO(3) were significantly higher in comparison with microorganisms treated with NaClO(4) (5.2-6.8 and 4.1-4.7 log(10) cfu - colony-forming units, respectively). A decrease in the ionic strength (0.1 M, 0.01 M and 0.005 M) of both electrolytes increased viable bacterial cell counts in NaNO(3) treatments and decreased viable bacterial counts in NaClO(4) treatments. Potentiometric titration revealed three dominant types of cell wall functional groups: the carboxyl group (pK(a) values of 4.58-4.89), the amino group (pK(a) values of 9.62-9.89) and the phosphate group (pK(a) values of 7.12-7.49). An increase in the ionic strength of electrolytes led to a decrease in total site concentrations and a drop in buffering capacity at the examined pH values. Based on zeta potential values, measured as a function of pH and ionic strength, the isoelectric point of B. subtilis was determined at pH 2.2 for 0.005 M and 0.01 M NaNO(3). Zeta potential increased with a rise in pH, and it decreased with an increase in ionic strength.