Characterization of Liposomes for Cancer Cell Transfection

We have characterized a broad range of liposome formulations with varying DcChol:DOPE ratio. Subsequent addition of DcChol to liposomes increases its positive surface charge. However, loading the nuclear acids did not neutralize the overall negative surface potential to a similar extent. The liposomes were tested by transfection of DNA in living cancer cells

Interactions between spherical nanoparticles optically trapped in Laguerre-Gaussian modes

When a Laguerre-Gaussian (LG) laser mode is used to trap nanoparticles, the spatial disposition of the particles about the beam axis is determined by a secondary mechanism that engages the input radiation with the interparticle potential. This analysis, based on the identification of a range-dependent laser-induced energy shift, elicits and details features that arise for spherical nanoparticles irradiated by a LG mode. Calculations of the absolute minima are performed for LG beams of variable topological charge, and the results are displayed graphically. It is shown that more complex ordered structures emerge on extension to three- and four-particle systems and that similar principles will apply to other kinds of radially structured optical mode. © 2005 Optical Society of America

Optically bound microscopic particles in one dimension

Counter-propagating light fields have the ability to create self-organized one-dimensional optically bound arrays of microscopic particles, where the light fields adapt to the particle locations and vice versa. We develop a theoretical model to describe this situation and show good agreement with recent experimental data (Phys. Rev. Lett. 89, 128301 (2002)) for two and three particles, if the scattering force is assumed to dominate the axial trapping of the particles. The extension of these ideas to two and three dimensional optically bound states is also discussed.Comment: 12 pages, incl. 5 figures, accepted by Phys. Rev.

SNP genes of immune response mediators and predisposition to development of socially significant diseases

Allele typing of single-nucleotide polymorphisms (SNPs) may be used in predictive medicine and to determine targets for the most effective treatment strategies for various diseases. The purpose of the present work was to investigate the association between the SNPs of inflammatory genes, e.g., IL10 (C819T; rs1800871; C592A; rs1800872); IL4 (C589T; rs2243250); fibrosis-related factors - TGFβ1 (G915C; rs1800471); MMP1 (1607insG; rs1799750); apoptosis-regulators (TNFRSF11B G1181C; rs2073618); vasoconstricting factors (CRP C3872T; rs1205); CYP1A1 (A2454G; rs1048943), endothelial dysfunction (EDN1 G925T; rs5370); (NOS3 C786T; rs2070744) and development of coronary heart disorders, breast cancer, bronchial asthma (BA) and threatened miscarriage in early pregnancy among population of the Republic of Adygea.DNA samples of unrelated donors and patients (n = 74) with verified diagnoses of bronchial asthma (n = 13), coronary heart disease (n = 10), breast cancer (n = 10) and threatened miscarriage in the first trimester of pregnancy (n = 8) were isolated from peripheral blood leukocytes and typed by allele-specific polymerase chain reaction with electrophoretic detection of results using commercial tests-systems of NPF “Litech”, Moscow.The study in a group of Adygea residents has revealed the statistical significance for the “normal” Arg25-allelic variant of the TGFβ1 gene (p < 0.05; F = 0.038; OR = 3.231; 95% CI = 1.081-9.656) in the development of bronchial asthma. There were no significant differences in SNP rs1800471 of the TGFβ1 gene in the groups with cardiovascular, oncological diseases and gestational disorders (p > 0.05). The frequency distribution of allelic variants NOS3 C786T; TNFRSF11B G1181C; 1607insG of the MMP1 gene; G925T of the EDN1 gene, and CYP1A1 2454G in the examined patients with cardiovascular disease and breast cancer did not significantly differ from the control group (p > 0.05). The statistical significance for the frequency of allelic variants rs1799750 (MMP1 gene) in cases of threatened early miscarriage and in women with a physiological course of pregnancy (F = 0.096; p < 0.05%: OR = 6.0) was close to reliable, but with a confidence interval > 1.0 (95% CI = 0,98036,716), thus requiring further research.The obtained data could be sufficient in order to suggest predisposition for bronchial asthma, as well as to develop a set of preventive measures taking into account the individual characteristics of each patient

Imbalance of NK cell subpopulations and polymorphisms of proinflammatory cytokine genes in the pathogenesis of atherosclerosis

Understanding the pathogenetic mechanism of development and identifying trigger markers of the disease will significantly increase the efficiency of pre-nosological diagnosis and medical follow-up of patients. In this case, one should take into account the role of mutations in cytokine genes, which affect their biochemical activity and production level. The objective of the study was to investigate the role of mediators of acute and chronic inflammation (IL-17A, IL-1â, TNFá and IL-4), the ratio of natural killer cell subpopulations (CD56hiCD16-/CD56loCD16+) in pathogenesis of coronary atherosclerosis resulting into coronary heart disease.To analyze the results, an integrated approach was used, including molecular genetic methods such as polymerase chain reaction, typing of single-nucleotide substitutions in cytokine genes, isolation and cultivation of peripheral blood mononuclear cells, assessment of spontaneous and in vitro-induced production of immune system mediators, enzyme-linked immunosorbent assay, cytotoxic test, flow cytometry with monoclonal antibodies (Beckman Coulter, USA) to CD16, CD56 NK markers.The study included 130 residents of the North Caucasus, including the patients (n = 62) treated at the Cardiology Department of the Adyghe Republican Clinical Hospital (ARCB) with a verified diagnosis of ischemic heart disease (IHD), and a control group (n = 68), represented by unrelated healthy donors.Overexpression of cytokines in IHD patients was associated with distinct single nucleotide substitutions in certain genes. Studying a group of residents from the Republic of Adygeya, the authors experimentally established that harboring the 511C allele of the IL-1â gene (p < 0.0004; OR = 4.67), A197A of the IL-17A gene genotype (p < 0.04; OR = 3.88), G308 SNP of TNFá gene (p < 0.01; OR = 3.41), and 589T variant of IL-4 gene (p < 0.04; OR = 2.45) are associated with hyperproduction of the first-wave inflammatory mediators that increase the risk of developing ischemic heart disease. In atherosclerosis and associated cardiovascular diseases, we have noted a significant decrease in spontaneous and induced activity of natural killer cells involved in the utilization of “foamy cells”. The NK activity of peripheral blood mononuclear cell in patients with coronary heart disease is significantly reduced. In the IHD patients, an imbalance of phenotypically and functionally different CD56hiCD16-/CD56loCD16+ NK subpopulations with a predominance of CD56hiCD16- phenotype were revealed. Conclusions: Immuno-inflammatory mechanisms of evolving coronary atherosclerosis are associated with single-nucleotide substitutions, i.e., polymorphisms in the promoter regions of the IL-17A (G197A), IL-1 â (T511C), and TNFá (G308A), the known mediators of acute and chronic inflammation.Genetically determined overexpression of IL-17A, IL-1â, and TNFá, confirmed in experiments on evaluation of spontaneous and stimulated cytokine production in patients with CHD, together with reduced NK activity of РВМС, due to predominance of CD56hiCD16-, a subpopulation with high cytokine production, manifested by an increased pro-inflammatory component that triggers and provides long-term support to pathophysiological processes of atherosclerosis

Nonlinear electrophoresis of dielectric and metal spheres in a nematic liquid crystal

Electrophoresis is a motion of charged dispersed particles relative to a fluid in a uniform electric field. The effect is widely used to separate macromolecules, to assemble colloidal structures, to transport particles in nano- and micro-fluidic devices and displays. Typically, the fluid is isotropic (for example, water) and the electrophoretic velocity is linearly proportional to the electric field. In linear electrophoresis, only a direct current (DC) field can drive the particles. An alternate current (AC) field is more desirable because it allows one to overcome problems such as electrolysis and absence of steady flows. Here we show that when the electrophoresis is performed in a nematic fluid, the effect becomes strongly non-linear with a velocity component that is quadratic in the applied voltage and has a direction that generally differs from the direction of linear velocity. The new phenomenon is caused by distortions of the LC orientation around the particle that break the fore-aft (or left-right) symmetry. The effect allows one to transport both charged and neutral particles, even when the particles themselves are perfectly symmetric (spherical), thus enabling new approaches in display technologies, colloidal assembly, separation, microfluidic and micromotor applications.Comment: 15 pages, 4 figure

Gene polymorphisms of IL-1β (C511T), IL-17A (G197A), IL-12B (A1188C), TNFα (G308A) and IL-4 (C589T) associated with threat of early reproductive losses

Prevalence of threatened miscarriage is 16-25% of all pregnancies. The symptomatics of the threatened miscarriage in the first trimester may develop due to conversion of initial inflammatory reaction that disturbs the intersystemic and local interactions in the endometrium, followed by placental insufficiency, intrauterine fetal affection and spontaneous abortion. The aim of our work was to study the association between single nucleotide polymorphisms (SNPs) of some cytokine genes, e.g., IL-1β (C511T, rs16944), IL-17A (G197A, rs2275913), IL-12B (A1188C, rs3212227), TNFα (G308A, rs1800629), and IL-4 (C589T, rs2243250) and the risk of early reproductive losses among residents of Adyghe Republic (RA). The work was carried out at the Immunogenetic Laboratory of our Research Institute of Complex Problems. The allelic variants of cytokine genes were detected by SNP-method in 106 samples of genomic DNA in women with the threatened abortion in 1st trimester (n = 58) and the uncomplicated gestation (n = 48). SNP-typing of polymorphic variants of cytokine genes IL-1β, IL-17A, IL-12B, TNFα and IL-4 was carried out by PCR (polymerase chain reaction) with allele-specific primers and electrophoretic detection of results on test systems of (Litech, Moscow). Statistical analysis of experimental data was carried out by SPSS Statistical program 17.0. The correspondence of SNP distributions to expected values at Hardy—Weinberg equilibrium and comparison of allelic variants/ genotypes frequencies were performed using the χ2 criterion (Chi-square with Yates correction), odd ratios (OR) detected at significance level p < 0.05 and 95% confidence interval (95% CI). Reliability of the differences for the SNP frequencies for small samples was evaluated using the Fisher’s exact criterion. Heterozygous variant (C511T; OR = 3.46; 95% Cl: 1.04-11.54) and homozygous “mutant” genotypes (T511T; OR = 5.71; 95% Cl: 1.12-29.09) of the main proinflammatory IL-1β was significantly associated (p < 0.05) with the risk of developing threatening miscarriage in the Adygea residents. The -511Т allele of IL-1β gene, and -1188C variant of IL-12B gene increase the risk of the early termination of pregnancy, respectively, 5.8-fold (95% Cl: 2.4213.92; p = 0.00004), and 2.97-fold (95% Cl: 1.23-7.19; p = 0.01). The “mutant” -511T allelic variant of the IL-1 p gene is associated with the risk of developing a symptome complex of threatening miscarriage in Russian ethnic group (p = 0.0001; OR = 14.09), and in Adygea ethnic group (p = 0.02; OR = 8.17), which is almost undetectable in women with normal pregnancy in the first trimester. Thus, only С511Т (rs16944) in IL-1β gene and A1188C (rs3212227) in IL-12B gene of the five typed cytokine genes may be used as marker polymorphisms of gestational distress for the women in Adygea

Phonons in a one-dimensional microfluidic crystal

The development of a general theoretical framework for describing the behaviour of a crystal driven far from equilibrium has proved difficult1. Microfluidic crystals, formed by the introduction of droplets of immiscible fluid into a liquid-filled channel, provide a convenient means to explore and develop models to describe non-equilibrium dynamics2, 3, 4, 5, 6, 7, 8, 9, 10, 11. Owing to the fact that these systems operate at low Reynolds number (Re), in which viscous dissipation of energy dominates inertial effects, vibrations are expected to be over-damped and contribute little to their dynamics12, 13, 14. Against such expectations, we report the emergence of collective normal vibrational modes (equivalent to acoustic 'phonons') in a one-dimensional microfluidic crystal of water-in-oil droplets at Reapprox10-4. These phonons propagate at an ultra-low sound velocity of approx100 mum s-1 and frequencies of a few hertz, exhibit unusual dispersion relations markedly different to those of harmonic crystals, and give rise to a variety of crystal instabilities that could have implications for the design of commercial microfluidic systems. First-principles theory shows that these phonons are an outcome of the symmetry-breaking flow field that induces long-range inter-droplet interactions, similar in nature to those observed in many other systems including dusty plasma crystals15, 16, vortices in superconductors17, 18, active membranes19 and nucleoprotein filaments20.Comment: https://www.weizmann.ac.il/complex/tlusty/papers/NaturePhys2006.pd