Top-down and bottom-up approaches in production of aqueous nanocolloids of low solubility drug paclitaxel.

Nano-encapsulation of a poorly soluble anticancer drug was demonstrated with a sonication assisted layer-by-layer polyelectrolyte coating (SLbL). We changed the strategy of LbL-encapsulation from making microcapsules with many layers in the walls for encasing highly soluble materials to using a very thin polycation/polyanion coating on low solubility nanoparticles to provide them with good colloidal stability. SLbL encapsulation of paclitaxel resulted in stable 100-200 nm diameter colloids with a high electrical surface ξ-potential (of -45 mV) and drug content in the nanoparticles of 90 wt%. In the top-down approach, nanocolloids were prepared by rupturing a powder of paclitaxel using ultrasonication and simultaneous sequential adsorption of oppositely charged biocompatible polyelectrolytes. In the bottom-up approach paclitaxel was dissolved in organic solvent (ethanol or acetone), and drug nucleation was initiated by the addition of aqueous polyelectrolyte assisted by ultrasonication. Paclitaxel release rates from such nanocapsules were controlled by assembling multilayer shells with variable thicknesses and were in the range of 10-20 h.

[Study of genetic determination of base clinical components of metabolic syndrome].

Genetic analysis was carried out on the material including clinic and genealogical data about 510 patients with type 2 Diabetes Mellitus, 445 Essential Hypertension individuals, 239 abdominal obesity persons and their 1st degree relatives. It has been shown that the Essential Hypertension and abdominal obesity distribution in the population and families can be described by means of a variants polygene model with essential influence of the major genes. Gene complexes of predisposition to obesity, Essential Hypertension and Type 2 Diabetes Mellitus are independent, however, their liabilities are covered.

[Isolation of mycobacteria on different growth media and their identification].

AIM: To compare results of isolation of mycobacteria on different growth media. MATERIALS AND METHODS: From August 2005 to September 2008 Central Bacteriological Laboratory of MSPCTC performed 111,029 inoculations of clinical samples, isolated 14,513 (13.5%) cultures of mycobacteria, of which 14,095 (97.1%) belonged to M. tuberculosis complex and 418 (2.9%)--to non-tuberculous mycobacteria (NTM). RESULTS: Two thirds of isolated NTM belonged to slowly growing NTM (Ranyon classification), of which bacteria from M. avium complex as well as M. kansasii and M. xenopi predominated. M. fortuitum was the most frequently isolated between rapidly growing NTM. CONCLUSION: For isolation and identification of NTM the optimal was inoculation on at least 2 media: solid agar (Middlebrook 7H11) or egg medium and liquid medium (Middlebrook 7H9, in automated system BACTEC MGIT 960), each of which has its own advantages.

"SMART" drug delivery systems: double-targeted pH-responsive pharmaceutical nanocarriers.

To develop targeted pharmaceutical carriers additionally capable of responding to certain local stimuli, such as decreased pH values in tumors or infarcts, targeted long-circulating PEGylated liposomes and PEG-phosphatidylethanolamine (PEG-PE)-based micelles have been prepared with several functions. First, they are capable of targeting a specific cell or organ by attaching the monoclonal antimyosin antibody 2G4 to their surface via pNP-PEG-PE moieties. Second, these liposomes and micelles were additionally modified with biotin or TAT peptide (TATp) moieties attached to the surface of the nanocarrier by using biotin-PE or TATp-PE or TATp-short PEG-PE derivatives. PEG-PE used for liposome surface modification or for micelle preparation was made degradable by inserting the pH-sensitive hydrazone bond between PEG and PE (PEG-Hz-PE). Under normal pH values, biotin and TATp functions on the surface of nanocarriers were "shielded" by long protecting PEG chains (pH-degradable PEG(2000)-PE or PEG(5000)-PE) or by even longer pNP-PEG-PE moieties used to attach antibodies to the nanocarrier (non-pH-degradable PEG(3400)-PE or PEG(5000)-PE). At pH 7.4-8.0, both liposomes and micelles demonstrated high specific binding with 2G4 antibody substrate, myosin, but very limited binding on an avidin column (biotin-containing nanocarriers) or internalization by NIH/3T3 or U-87 cells (TATp-containing nanocarriers). However, upon brief incubation (15-30 min) at lower pH values (pH 5.0-6.0), nanocarriers lost their protective PEG shell because of acidic hydrolysis of PEG-Hz-PE and acquired the ability to become strongly retained on an avidin column (biotin-containing nanocarriers) or effectively internalized by cells via TATp moieties (TATp-containing nanocarriers). We consider this result as the first step in the development of multifunctional stimuli-sensitive pharmaceutical nanocarriers.

[Biological characterization and prospects of application of a new bifidobacterial strain as an ingradient of probiotics].

The study was dedicated to investigation of a bifidobacterial strain, isolated from a healthy chick, its biological properties and lectins produced by the strain; a restrictive analysis of the chromosomal DNA was conducted as well. Presumably B. gallinarum was identified. The strain displayed adhesive, lectinic and antagonistic activities; it was resistant to the leading chemotherapeutic pharmaceuticals and antibiotics, and, when given to chicks, it had probiotic effect. The study identified a set of lectins binding phosphorylated mannan, with isoelectric points in the pH interval of 4 to 8; the set differed from the sets of lectins of other bifidobacteria.

ATP-loaded liposomes effectively protect mechanical functions of the myocardium from global ischemia in an isolated rat heart model.

ATP-loaded liposomes (ATP-L) infused into Langendorff-instrumented isolated rat hearts protect the mechanical functions of the myocardium during ischemia/reperfusion. The left ventricular developed pressure (LVDP) at the end of the reperfusion in the ATP-L group recovered to 72% of the baseline (preservation of the systolic function) compared to 26%, 40%, and 51% in the groups treated with Krebs-Henseleit (KH) buffer, empty liposomes (EL), and free ATP (F-ATP), respectively. The ATP-L-treated group also showed a significantly lower left ventricular end diastolic pressure (LVEDP; better preservation of the diastolic function) after ischemia/reperfusion than controls. After incubating the F-ATP and ATP-L with ATPase, the protective effect of the F-ATP was completely eliminated because of ATP degradation, while the protective effect of the ATP-L remained unchanged. Fluorescence microscopy confirmed the accumulation of liposomes in ischemic areas, and the net ATP in the ischemic heart increased with ATP-L. Our results suggest that ATP-L can effectively protect myocardium from ischemic/reperfusion damage.

Encapsulation of ATP into liposomes by different methods: optimization of the procedure.

Different methods and conditions for ATP incorporation into PEGylated liposomes were compared in order to obtain a preparation with a maximized ATP content. Such a preparation may find the application for the in vivo treatment of ischemic tissues suffering from an insufficient ATP supply. Several different methods of liposome preparation and purification were used and HPLC was employed to determine the concentration of ATP in the liposomes. Thin lipid film hydration produced vesicles with the lowest ATP encapsulation (ca. 5 mol%). A pH gradient method yielded liposomes with ca. 10 mol% of ATP. Reverse phase evaporation and freezing-thawing methods resulted in a maximum entrapment of ATP on the level of 36-38 mol%. The freezing-thawing method was chosen for further investigation because of its simplicity and absence of a need to use organic solvents. The separation of the non-entrapped ATP by gel-filtration, centrifugation or dialysis yielded virtually identical liposomal preparations. The incorporation of PEG (as PEG-distearoyl phosphatidylethanolamine, PEG-DSPE) into the liposomal membrane decreases the quantity of the entrapped ATP (from 38 mol% for liposomes with 0.5 mol% of PEG-DSPE to only 17 mol% for liposomes with 5 mol% of PEG-DSPE).

TAT-liposomes: a novel intracellular drug carrier.

TAT peptide was attached to the surface of plain and PEGylated liposomes. These TAT peptide-modified liposomes have been shown to translocate into a variety of normal and cancer cells if a non-hindered interaction between the cell surface and liposome-attached TAT peptide was made possible. TAT peptide-liposomes translocated into cells remain intact within first few hours as proved by a co-localization of fluorescent markers entrapped inside liposomes and incorporated into the liposomal membrane. After 2 hours liposomes had slowly migrating towards cell nuclei. Liposomes had completely disintegrated with their inner marker released by approximately 9 hours. TAT peptide-liposomes were made slightly cationic by adding up to 10 mol %. of a cationic lipid (DOTAP). These slightly cationic liposomes were non-toxic towards cells, formed firm complexes with DNA (plasmid encoding for the formation of the Green Fluorescent Protein), and efficiently transfected a variety of cells. TAT peptide-liposomes can be considered as promising carriers for the non-endocytotic intracellular delivery of drugs and DNA.

[Tobacco smoke condensate-induced structural changes in Mycobacteria tuberculosis]. / Izmenenie struktury mikobakterii tuberkuleza pod deistviem kondensata tabachnogo dyma.

The paper shows how a tobacco smoke condensate affects the anatomy of Mycobacteria tuberculosis. Gas chromatography was used to detect quantitative changes in the composition of fatty acids. Electron microscopy indicated larger microcolonies, thickened lipid capsular cover, increased number of polysomes in experimental mycobacterial strains.

Amphiphilic poly-N-vinylpyrrolidones: synthesis, properties and liposome surface modification.

Certain amphiphilic water-soluble polymers including amphiphilic derivatives of polyvinyl pyrrolidone (PVP) were found to be efficient steric protectors for liposomes in vivo. In this study, we have tried to develop synthetic pathways for preparing amphiphilic PVP and to investigate the influence of the hydrophilic/hydrophobic blocks on some properties of resulting polymers and polymer-coated liposomes. To prepare amphiphilic PVP with the end stearyl (S) or palmityl (P) residues, amino- and carboxy-terminated PVP derivatives were first synthesized by the free-radical polymerization of vinyl pyrrolidone in the presence of amino- or carboxy-mercaptans as chain transfer agents, and then modified by interaction of amino-PVP with stearoyl chloride or palmitoyl chloride, or by dicyclohexyl carbodiimide coupling of stearylamine with carboxy-PVP. ESR-spectra of the hydrophobic spin-probe, nitroxyl radical N-oxyl-2-hexyl-2-(10-methoxycarbonyl)decyl-4,4'-dimethyl oxazoline, in the presence of amphiphilic PVP demonstrated good accessibility of terminal P- and S-groups for the interaction with other hydrophobic ligands. Spontaneous micellization and low CMC values (in a low micromolar range) were found for amphiphilic PVP derivatives using the pyrene method. In general, S-PVP forms more stable micelles than P-PVP (at similar MW, CMC values for S-PVP are lower than for P-PVP). It was found that amphiphilic PVP incorporated into negatively charged liposomes effectively prevents polycation(poly-ethylpyridinium-4-vinylchloride)-induced liposome aggregation, completely abolishing it at ca. 10 mol% polymer content in liposomes. Additionally, the liposome-incorporated PVP prevents the fluorescence quenching of the membrane-incorporated hydrophobic fluorescent label [N-(4-fluoresceinthiocarbamoyl)dipalmitoyl-PE] by the free polycation. PVP-modified liposomes were loaded with a self-quenching concentration of carboxyfluorescein, and their destabilization in the presence of mouse serum was investigated following the release of free dye. Amphiphilic PVP with MW between 1,500 and 8,000 provides good steric protection for liposomes. The degree of this protection depends on both polymer concentration and molecular size of the PVP block.

TAT peptide on the surface of liposomes affords their efficient intracellular delivery even at low temperature and in the presence of metabolic inhibitors.

To achieve an efficient intracellular drug and DNA delivery, attempts were made to target microparticulate drug carriers into cytoplasm bypassing the endocytotic pathway. TAT peptides derived from the HIV-1 TAT protein facilitate intracellular delivery of proteins and small colloidal particles. We demonstrated that relatively large drug carriers, such as 200-nm liposomes, can also be delivered into cells by TAT peptide attached to the liposome surface. Liposomes were fluorescently labeled with membranotropic rhodamine-phosphatidylethanolamine or by entrapping FITC-dextran. Incubation of fluorescent TAT liposomes with mouse Lewis lung carcinoma cells, human breast tumor BT20 cells, and rat cardiac myocyte H9C2 results in intracellular localization of certain liposomes. Steric hindrances for TAT peptide x cell interaction (attachment of TAT directly to the liposome surface without spacer or the presence of a high MW polyethylene glycol on the liposome surface) abolish liposome internalization, evidencing the importance of direct contact of TAT peptide with the cell surface. Low temperature or metabolic inhibitors, sodium azide or iodoacetamide, have little influence on the translocation of TAT liposomes into cells, confirming the energy-independent character of this process. The approach may have important implications for drug delivery directly into cell cytoplasm.

Negatively charged polymers protect antinuclear antibody against inactivation by acylating agents.

For many practical applications, monoclonal antibodies must be chemically modified without any significant loss in their immunoreactivity. In some situations, however, the amino acid residue crucial for antibody activity may be highly reactive toward the modifying agent, which results in antibody inactivation. The method to prevent inactivation of a modification-sensitive antinuclear monoclonal antibody by acylating agents was developed. The method is based on the hypothesis that a highly reactive amino group exists within, or in the vicinity of, the binding site of the antibody, providing crucial interaction with negatively charged moieties of DNA. It has been shown that negatively charged polymers, such as dextran sulfate or heparin, may provide temporary protection, presumably interacting noncovalently with this amino group and thus masking it. The protecting molecule can be removed later by chromatography on a protein A column, thus regenerating modified but not inactivated antibody in the free form for use in subsequent applications. In particular, we have modified antibody 2C5 with a chelating agent, diethylenetriaminepentaacetic acid (DTPA) without the loss of activity. Modified antibody was labeled with radioactive isotope, (111)In, via chelation by antibody-attached DTPA. The labeled antibody was shown to demonstrate the same specificity of binding to nucleosomes as the nonmodified antibody, so it may be used in immunoscintigraphy or biodistribution studies. The method might be useful for the modification of other modification-sensitive antibodies with other acylating chemicals, such as crosslinking agents or biotin derivatives.

p-Nitrophenylcarbonyl-PEG-PE-liposomes: fast and simple attachment of specific ligands, including monoclonal antibodies, to distal ends of PEG chains via p-nitrophenylcarbonyl groups.

We have attempted to simplify the procedure for coupling various ligands to distal ends of liposome-grafted polyethylene glycol (PEG) chains and to make it applicable for single-step binding of a large variety of a primary amino group-containing substances, including proteins and small molecules. With this in mind, we have introduced a new amphiphilic PEG derivative, p-nitrophenylcarbonyl-PEG-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (pNP-PEG-DOPE), synthesized by reaction of DOPE with excess of bis(p-nitrophenylcarbonyl)-PEG in a chloroform/triethylamine mixture. pNP-PEG-DOPE readily incorporates into liposomes via its PE residue, and easily binds primary amino group-containing ligands via its water-exposed pNP groups, forming stable and non-toxic urethane (carbamate) bonds. The reaction between the pNP group and the ligand amino group proceeds easily and quantitatively at pH around 8.0, and remaining free pNP groups are promptly eliminated by spontaneous hydrolysis. Therefore, pNP-PEG-DOPE could serve as a very convenient tool for protein attachment to the distal ends of liposome-grafted PEG chains. To investigate the applicability of the suggested protocol for the preparation of long-circulating targeted liposomes, we have coupled several proteins, such as concanavalin A (ConA), wheat germ agglutinin (WGA), avidin, monoclonal antimyosin antibody 2G4 (mon2G4), and monoclonal antinucleosome antibody 2C5 (mon2C5) to PEG-liposomes via terminal pNP groups and studied whether the specific activity of these immobilized proteins is preserved. The method permits the binding of several dozens protein molecules per single 200 nm liposome. All bound proteins completely preserve their specific activity. Lectin-liposomes are agglutinated by the appropriate polyvalent substrates (mannan for ConA-liposomes and glycophorin for WGA-liposomes); avidin-liposomes specifically bind with biotin-agarose; antibody-liposomes demonstrate high specific binding to the substrate monolayer both in the direct binding assay and in ELISA. A comparison of the suggested method with the method of direct membrane incorporation was made. The effect of the concentration of liposome-grafted PEG on the preservation of specific protein activity in different coupling protocols was also investigated. It was also shown that pNP-PEG-DOPE-liposomes with and without attached ligands demonstrate increased stability in mouse serum.

Angiomotin: an angiostatin binding protein that regulates endothelial cell migration and tube formation.

Angiostatin, a circulating inhibitor of angiogenesis, was identified by its ability to maintain dormancy of established metastases in vivo. In vitro, angiostatin inhibits endothelial cell migration, proliferation, and tube formation, and induces apoptosis in a cell type-specific manner. We have used a construct encoding the kringle domains 1--4 of angiostatin to screen a placenta yeast two-hybrid cDNA library for angiostatin-binding peptides. Here we report the identification of angiomotin, a novel protein that mediates angiostatin inhibition of migration and tube formation of endothelial cells. In vivo, angiomotin is expressed in the endothelial cells of capillaries as well as larger vessels of the human placenta. Upon expression of angiomotin in HeLa cells, angiomotin bound and internalized fluorescein-labeled angiostatin. Transfected angiomotin as well as endogenous angiomotin protein were localized to the leading edge of migrating endothelial cells. Expression of angiomotin in endothelial cells resulted in increased cell migration, suggesting a stimulatory role of angiomotin in cell motility. However, treatment with angiostatin inhibited migration and tube formation in angiomotin-expressing cells but not in control cells. These findings indicate that angiostatin inhibits cell migration by interfering with angiomotin activity in endothelial cells.

[Mechanism of action of lomefloxacin on Mycobacterium tuberculosis]. / Osobennosti mekhanizma deistviia lomefloksatsina na mikobakterii tuberkuleza.

The peculiarities of the mechanism of the lomefloxacin bactericidal action on Mycobacterium tuberculosis were studied. The electron microscopy of ultrathin sections of the cells of M.tuberculosis H37Rv exposed to 10 micrograms/ml of lomefloxacin for 24 hours revealed severe changes in their ultrastructure: exfoliation of the cell wall from the cytoplasmic membrane, loosening and fragmentation of the cytoplasmic membrane, lowering of the cytoplasm thickness, vacuolization and twisting of the mesosomes. The exposure of the cells to lomefloxacin for 72 hours resulted in their complete destruction: the cells proved to be a mass of unidentifiable fragments. Some destructions such as exfoliation of the intracytoplasmic membrane and the cytoplasm loosening and vacuolization were observed in the tubercle bacilli localized inside the phagosomes of the murine lung macrophages exposed to lomefloxacin. Such destructions were evident of the antibiotic good penetration not only into the macrophages but also through the phagosome walls as well as of the lomefloxacin intracellular bactericidal activity. In the experiments with the culture of the lung tissue from the tuberculosis foci of mice the basic mechanism fo the lomefloxacin action on M.tuberculosis was demonstrated: the lomefloxacin bactericidal effect was realized through the pathway of mechanism A of the antimicrobial action of fluoroquinolones.

[Ultrastructural organization of tuberculosis mycobacteria]. / Ul'trastrukturnaia organizatsiia mikobakterii tuberkuleza.

Methodological approaches--cryoultratomy and high-voltage electron microscopy of whole cell--have been used for studying the ultrastructural organization of the tuberculous mycobacteria of the virulent H37Rv strain and BCG vaccine strain. The anatomic difference has been found between the virulent and vaccine strains, which can undoubtedly be taken as a strain difference. The presence of a developed lipid capsule sheath has been confirmed and the size of separate mycobacterial species defined more accurately.

[The use of antioxidants in the complex therapy of patients with infiltrating pulmonary tuberculosis]. / Primenenie antioksidantov v kompleksnom lechenii bol'nykh infil'trativnym tuberkulezom legkikh.

Clinical and laboratory investigations examined the possibility of a lower load of antibacterial drugs (ABD) in combination with the two antioxidants, alpha-tocopherol and sodium thiosulfate, in combined therapy of patients with infiltrative pulmonary tuberculosis. Higher efficacy of two ABDs supplemented by two antioxidants than three or more ABDs was evidenced by a shorter period of sputum negativity (1.6 +/- 0.26 and 2.7 +/- 0.27 months; p less than 0.01) and higher rates of cavity closure (95.6 +/- 4.3 and 63.2 +/- 6.7%; p less than 0.05).

[Effect of low-energy helium-neon laser on the biological properties of Mycobacterium tuberculosis]. / Vliianie nizkoénergeticheskogo gelii-neonovogo lazera na biologicheskie svoistva mikobakterii tuberkuleza.

The results of experimental studies of M. tuberculosis biological properties tested in guinea pigs which were subjected to different doses of helium-neon laser radiation are given. The functional evidence is compared with the results of electron microscopic study of the irradiated culture. The investigation revealed that laser radiation caused changes in biological properties of M. tuberculosis. A decrease in growth properties and virulence was found to be related to a radiation dose. It is suggested that a drop in the biological activity of M. tuberculosis under laser radiation be associated with its influence on the Mycobacterium lipid layer which contains a cord-factor and responsible for their virulence.

[Short- and long-term results of intensive insulin therapy in patients with severe forms of diabetes mellitus type I]. / Neposredstvennye i otdalennye rezul'taty intensivnoi insulinoterapii bol'nykh s tiazhelymi formami sakharnogo diabeta I tipa.

Short- (3-4 week) and long-term (1-4 yrs) results of the use of intensive insulin therapy schemes were used in 37 patients with severe forms of type I diabetes mellitus. Its beneficial effect on metabolism, remaining secretory beta-cell function, the frequency and expression of hypoglycemic reactions, manifestations of peripheral and visceral neuropathy, diabetic encephalopathy was proved.