Inhibition of matrix metalloproteinases and cancer cell detachment by Ru(II) polypyridyl complexes containing 4,7-diphenyl-1,10-phenanthroline ligands : new candidates for antimetastatic agents

Primary tumor targeting is the dominant approach in drug development, while metastasis is the leading cause of cancer death. Therefore, in addition to the cytotoxic activity of a series of Ru(II) polypyridyl complexes of the type [Ru(dip)(2)L](2+) (dip: 4,7-diphenyl-1,10-phenanthroline while L = dip; bpy: 2,2′-bipyridine; bpy-SC: bipyridine derivative bearing a semicarbazone 2-formylopyridine moiety; dpq, dpq(CH(3))(2), dpb: quinoxaline derivatives) their ability to inhibit cell detachment was investigated. In vitro studies performed on lung cancer A549 cells showed that they accumulate in cells very well and exhibit moderate cytotoxicity with IC(50) ranging from 4 to 13 µM. Three of the studied compounds that have dip, bpy-SC, or dpb ligands after treatment of the cells with a non-toxic dose (<(1)/(2)IC(50)) enhanced their adhesion properties demonstrated by lower detachment in the trypsin resistance assay. The same complexes inhibited both MMP-2 and MMP-9 enzyme activities with IC(50) ranging from 2 to 12 µM; however, the MMP-9 inhibition was stronger. More detailed studies for [Ru(dip)(2)(bpy-SC)](2+), which induced the greatest increase in cell adhesion, revealed that it is predominately accumulated in the cytoskeletal fraction of A549 cells. Moreover, cells treated with this compound showed the localization of MMP-9 to a greater extent also in the cytoskeleton. Taken together, our results indicate the possibility of a reduction of metastatic cells escaping from the primary lesion to the surrounding tissue by prevention of their detachment and by influencing the activity of MMP-2 and MMP-9

Impact of Polypyridyl Ru Complexes on Angiogenesis&mdash;Contribution to Their Antimetastatic Activity

The use of polypyridyl Ru complexes to inhibit metastasis is a novel approach, and recent studies have shown promising results. We have reported recently that Ru (II) complexes gathering two 4,7-diphenyl-1,10-phenanthroline (dip) ligands and the one being 2,2&prime;-bipyridine (bpy) or its derivative with a 4-[3-(2-nitro-1H-imidazol-1-yl)propyl (bpy-NitroIm) or 5-(4-{4&prime;-methyl-[2,2&prime;-bipyridine]-4-yl}but-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (bpy-SC) moieties can alter the metastatic cascade, among others, by modulating cell adhesion properties. In this work, we show further studies of this group of complexes by evaluating their effect on HMEC-1 endothelial cells. While all the tested complexes significantly inhibited the endothelial cell migration, Ru-bpy additionally interrupted the pseudovessels formation. Functional changes in endothelial cells might arise from the impact of the studied compounds on cell elasticity and expression of proteins (vinculin and paxillin) involved in focal adhesions. Furthermore, molecular studies showed that complexes modulate the expression of cell adhesion molecules, which has been suggested to be one of the factors that mediate the activation of angiogenesis. Based on the performed studies, we can conclude that the investigated polypyridyl Ru (II) complexes can deregulate the functionality of endothelial cells which may lead to the inhibition of angiogenesis

The use of electrodes of Au thin-film onto a nanoporous Al2O3 for the determination of adrenaline

Celem niniejszej pracy była synteza elektrody na bazie nanozłota oraz jej zastosowanie w charakterze sensora adrenaliny o wysokiej czułości. Badania polegały na wyznaczeniu zależności natężenia prądu od zmian stężenia adrenaliny w układzie. Pomiary przeprowadzono w trójelektrodowym układzie doświadczalnym z wykorzystaniem potencjostatu Gamry. Wykonano testy potwierdzające powtarzalność wyników oraz sprawdzono wpływ obecność kwasu solnego w roztworze na otrzymany sygnał. Zbadano również zależności gęstości prądu od potencjału przy zmianie szybkości skanowania. Ostatnim etapem badań była ocena przewagi zastosowanej nanozłotej elektrody względem elektrody makroskopowej w zakresie przebadanych stężeń.The aim of this study was to synthesize nanostructured gold electrode, and to investigate its potential application as an highly sensitive electrochemical adrenaline sensor. The study was based on determination of the dependence between maximum peak current and concentration of an adrenaline in the system by using linear sweep voltammetry technique. All measurements were carried out in a typical three-electrode cell. The reproducibility of the results was confirmed and the effect of hydrochloric acid on the received signal was studied. The dependence of peak currents on the scan rate was also investigaded. Finally, the performance of as obtained nanostructured electrode was compared with an macroscopic electrode in the whole range of concentrations tested

Study on the potential use of cationic polymers as internal cryoprotectants, synthesis and optimization of new molecular cryopreservation systems.

Praca zawiera wyniki badań nad możliwością wykorzystania substancji wielkocząsteczkowych w procesie kriokonserwacji komórek. Przeprowadzono badania biologiczne na komórkach linii melanoma B16 oraz MEF. Pierwszym elementem pracy była synteza oraz badanie własności krioprotekcyjnych polimeru szczepionego dekstran––PEG w porównaniu z dimetylosulfotlenikiem (DMSO), poli(tlenkiem etylenu) (PEG) oraz dekstranem. W czasie tego eksperymentu zbadano także wpływ masy molekularnej polimeru na jego własności krioprotekcyjne. W kolejnej części badano możliwości wykorzystania dekstranu jako krioprotektanta wewnętrznego oraz wpływu jego dodatku na własności innych krioprotektantów. Badano także możliwość wykorzystania trehalozy jako krioprotektanta zewnątrz i wewnątrz komórkowego oraz hipotezę mówiącą, że polimer blokowy PAMPS75-PAaU39 zapewni transport trehalozy przez błonę komórkową. Ostatnim elementem pracy było badanie własności krioprotekcyjnych mieszanin dimetylosulotlenku (DMSO) oraz poliakrylamidu (PAA). W tej części zbadano też wpływ stężenia DMSO oraz PAA na ich własności krioprotekcyjne oraz wpływ zawartości surowicy w układzie.The thesis contains the results of studies on the use of high molecular weight substances in the process of cells cryopreservation. Studies were conducted on cells lines melanoma B16 and MEF. The first were the synthesis and investigation of the cryoprotective properties of the copolymer dextran- graft – PEG compared to dimethyl sulfoxide (DMSO), poly(ethylene oxide) (PEG) and dextran. During this experiment, the effect of molecular weight of polymer on its cryoprotective properties was also investigated. In the next part the possibility of using dextran as an internal cryoprotectant and its effect on the properties of other cryoprotectants were stadied. The possibility of using trehalose as an external and internal cryoprotectant and the hypothesis that the PAMPS75-PAaU39 block polymer will provide trehalose transport across the cell membrane have been also investigated. The last element of the study was the investigation of cryoprotective properties of dimethylsulfoxide (DMSO) and polyacrylamide (PAA) mixtures. In this part, the influence of DMSO and PAA concentration on their cryoprotective properties and influence of serum content were also investigated

Inhibition of Metastasis by Polypyridyl Ru(II) Complexes through Modification of Cancer Cell Adhesion – In Vitro Functional and Molecular Studies

International audienceThe effect of polypyridyl Ru(II) complexes on the ability of cancer cells to migrate and invade, two features important in the formation of metastases, is evaluated. In vitro studies are carried out on breast cancer cell lines, MDA-MB-231 and MCF-7, as well as melanoma cell lines A2058 and A375. Three Ru(II) complexes comprising two 4,7-diphenyl-1,10-phenanthroline (dip) ligands and as a third ligand 2,2′-bipyridine (bpy), or its derivative with either 4-[3-(2-nitro-1H-imidazol-1-yl)propyl] (bpy-NitroIm), or 5-(4-{4′-methyl-[2,2′-bipyridine]-4-yl}but-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (bpy-SC) moiety attached are examined. The low sub-toxic doses of the studied compounds greatly affected the cancer cells by inhibiting cell detachment, migration, invasion, transmigration, and re-adhesion, as well as increasing cell elasticity. The molecular studies revealed that the Ru(II) polypyridyl complexes impact the activity of the selected integrins and upregulate the expression of focal adhesion components such as vinculin and paxillin, leading to an increased number of focal adhesion contacts