Specificity of hexarhenium cluster anions for synthesis of Mn2+-based nanoparticles with lamellar shape and pH-induced leaching for specific organ selectivity in MRI contrasting.

The present work demonstrates the structure variation of hexarhenium anionic cluster units [{Re6S8}(CN)(6-n)(OH)n]4- (n = 0, 2, 4) as the strategy to develop Mn2+-containing nanoparticles (NPs) exhibiting pH-dependent leaching. The dicyanotetrahydroxo complex [{Re6S8}(CN)2(OH)4]4- is the optimal for the synthesis of the Mn2+-based NPs with a lamellar shape exhibiting the pH-dependent aggregation and magnetic relaxation behavior. The pH-dependent behavior of the NPs derives from the easy protonation of the apical hydroxo ligands of [{Re6S8}(CN)2(OH)4]4- cluster, which triggers partial leaching of Mn2+ ions and aggregation of the NPs driven by the surface neutralization. The in vivo MRI scanning of the mice intravenously injected with the NPs indicates the preferable accumulation of the lamellar NPs within mouse intestine over liver and kidneys. This differs from the spherical NPs constructed from [{Re6Se8}(CN)6]4- units, which provide the preferable brightening of mouse liver over kidneys and intestine.

Temperature-sensitive emission of dialkylaminostyrylhetarene dyes and their incorporation into phospholipid aggregates: Applicability for thermal sensing and cellular uptake behavior.

A series of dialkylaminostyrylhetarene dyes constructed from electron-rich and electron-deficient moieties of various structures connected via vinylene π-bridges are introduced as temperature-sensitive luminophores. The temperature dependent emission of the dyes in the acidified dichloromethane solutions derives from temperature-induced shift of the equilibrium between neutral and protonated forms of the dyes. The heating-induced blue shift and intensification of emission of neutral form of the dyes make them a promising basis for development of nanoparticles exhibiting temperature-sensitivity in aqueous solutions at pH typical of biological liquids. Hydrophobicity-driven incorporation of the water insoluble dyes into L-α-phosphatidylcholine(PC)-based bilayers allows to obtain water dispersible dye-PC aggregates, and to follow their emission in the aqueous solutions. Structure of the dyes has strong impact on the efficacy of the dyes incorporation into the PC-based bilayers, temperature sensitivity of emission of the dye-PC aggregates and its reversibility under the heating/cooling cycles. This enables structural optimization of the dyes in order to obtain the dye-PC species demonstrating maximal temperature dependence and reversibility of their luminescence in aqueous solutions. The selected leader exhibits low cytotoxicity exemplified for M-HeLa and Chang Liver cell lines, while the efficient cell internalization of the dye, manifested in the staining of the cell cytoplasm, opens further opportunities for biosensing applications.

Synthesis, structure-activity relationship and biological evaluation of tetracationic gemini Dabco-surfactants for transdermal liposomal formulations.

In this study, we report the relationship between structure, self-assembly behavior and antimicrobial activity of multicationic gemini surfactants and their successful use as stabilizers of a new liposomal formulation for transdermal drug delivery. New surfactants containing natural moiety 1,4-diazabicyclo[2.2.2]octane with four charges and two hydrophobic chains (n-Dabco-s-Dabco-n, where s = 2, 6, 12 and n = 12, 14, 16, 18) were synthesized. A linear dependence of the CMC decrease, with the increase of the number of carbon atoms in alkyl groups (slope 0.23) was shown. The aggregation numbers of n-Dabco-2-Dabco-n are smaller than 30 and they decrease with increasing alkyl chain length. This is in compliance with the larger surface area per n-Dabco-2-Dabco-n molecule. New liposomal formulations loading Rhodamine B phosphatidylcholine (with mean size about 100 nm and increased zeta potential from -7 ± 2 mV to +55 ± 2 mV) have been successfully stabilized by n-Dabco-s-Dabco-n surfactants. These formulations were designed to improve the bioavailability and skin permeation of loaded compound. The antibacterial activity of Dabco-surfactants was shown to be strongly affected by their structure (alkyl chain length and number of charged nitrogen). 12-Dabco-2-Dabco-12 was the most active (MIC = 0.48, 0.98 and 15.6 µg/mL against S. aureus, B. cereus and E. coli, respectively) without hemolytic activity at 3.1 µg/mL concentration. PC/14-Dabco-2-Dabco-14-liposomes were shown to be the best formulation, with the highest antibacterial activity against Sa (MIC = 7.8 µg‧mL-1) and lowest cytotoxicity (IC50 > 125). The modification of liposomes by Dabco-surfactants stabilizes the membrane of the vesicles, preventing the release of rhodamine B and impairing the penetration of the dye across Strat-M® membrane. Cellular uptake of rhodamine B-loaded PC/12-Dabco-2-Dabco-12-liposomes was also reported. This is the first example of cationic mixed liposomes containing Dabco-surfactants of potential interest for transdermal drug delivery.

[Immunomodulating activity of adhesive dental film containing chlorhexidine and ketoprofen in serum of patients with chronic periodontitis]. / Immunomoduliruiushchaia aktivnost' adgezivnoi plenki s khlorgeksidinom i ketoprofenom v krovi bol'nykh khronicheskim generalizovannym parodontitom.

The study was carried out in series of preclinical tests of new adhesive dental film developed for local treatment of inflammatory periodontal disease and containing chlorhexidine bigluconate and ketoprofen. The aim of the work was to determine film's effect on the activity of blood neutrophils in healthy individuals and in patients with chronic periodontitis using luminol-dependent chemiluminescence method. The investigated dental film showed modulating influence on blood phagocytes methabolism depending on their initial functional state. Immunomodulating activity revealed is associated with the polymer base and is potentiated by ketoprofen in case of hyporeactive inflammation.

The first representatives of tetranuclear gold(i) complexes of P,N-containing cyclophanes.

The first representatives of the tetranuclear gold(i) complexes of P,N-containing cyclophanes with two 1,5-diaza-3,7-diphosphacyclooctane rings incorporated into the macrocyclic core have been obtained. The complexation leads to a change in ligand conformations so that the diazadiphosphacyclooctane fragments of the complexes adopt twist-chair conformations, and two of the four gold(i) ions are located over and under the partially collapsed macrocyclic cavity. The complexes demonstrate moderate solid-state green emission.

Synthesis of novel pyridyl containing phospholanes and their polynuclear luminescent copper(i) complexes.

A novel type of cyclic P,N-ligands, pyridyl containing phospholanes, has been synthesized in a moderate yield by the reaction of primary phosphines with 1,4-dichlorobutane in a superbasic medium. A series of homo tetranuclear octahedral Cu4I4L2, dinuclear tetrahedral Cu2I2L3, and dinuclear "head-to-tail" Cu2I2L2 luminescent complexes with these ligands were obtained. All the compounds were characterized using a range of spectroscopic and computational techniques, and in the case of some Cu4I4L2 and Cu2I2L3 complexes, by single crystal X-ray diffraction. The structural diversity of the obtained complexes was reflected in their photophysical properties: phosphorescence spectra of the compounds display emission in broad spectral range of 471-615 nm. TD-DFT computations allow the assignment of a single emission band around 550 nm for Cu2I2L3 complexes and 471 nm for Cu2I2L2 complex to a vertical triplet-singlet transition from a metal-to-ligand and halide-to-ligand charge-transfer (3)(M + X)LCT excited state, whereas a second band at around 600 nm in the spectra of octahedral Cu4I4L2 complexes was assigned predominantly to Cu4I4 cluster-centered ((3)CC) excited state.

[Effect of statins on activity of matrix metalloproteases and serum concentration of cystatin C in patients with various risk of development of ischemic heart disease and in patients after coronary artery bypass surgery].

We compared new non-lipid atherosclerosis indexes related to inflammation and macrophage stimulation (serum concentration of cystatin C, matrix metalloproteases and chitotriosidase activity) with common inflammatory (high sensitivity C reactive protein) and lipid markers in elderly persons and patients with atherosclerosis and ischemic heart disease who have undergone coronary bypass surgery.