Effect of Cell-Penetrating Arginine Peptide on Interaction of Photosensitizer Chlorin e6 Incorporated into Phospholipid Nanoparticles with Tumor Cells.

We studied the possibility of increasing the efficiency of photodynamic therapy by improving delivery of photosensitizers chlorin e6 into tumor cells. Previous studies showed that incorporation of chlorin e6 onto phospholipid nanoparticles with a diameter <20 nm reduces its cytotoxicity due to accelerated elimination from organs [8]. A heptapeptide R7 synthesized and added to this combination promoted internalization of chlorin e6 into HepG2 cells in comparison with initial nanoparticles without peptide R7. The observed effect of peptide R7 can be explained by activation of endocytosis and/or macropinocytosis (bearing in mind the interaction of arginine with carboxyl groups of e6. The development of this transporting system is a promising trend in photodynamic therapy of cancer diseases.

[Prednisolone in phospholipid nanoparticles: prolonged circulation and increased antiinflammatory effect]. / Prednizolon v fosfolipidnykh nanochastitsakh: prolongirovannaia tsirkuliatsiia i povyshennoe protivovospalitel'noe deistvie.

Along with modern new drugs, many therapeutic schemes also include known effective drugs, particularly, glucocorticoids. One of the most distributed of them is prednisolone that has pronounced anti-inflammatory properties. Its disadvantage is short-term circulation, resulting in a number of side effects. For this reason the development of its more effective and safe formulations is carried out. We have obtained the formulation of prednisolone included in nanoparticles from soy phosphatidylcholine with an average diameter of 20 nm. With oral administration to rats and analysis by HPLC an increase in prednisolone maximal concentration in of plasma and the duration of circulation as compared with free drug administration were shown. The experiment with mice with conconavalin A induced inflammation was also carried out: conconavalin A was injected subplantary in an hour after oral administration of both prednisolone formulations in several doses. The index of the inflammatory reaction (determined by the edema degree) was suppressed more effectively in the case of prednisolone in nanoparticles. Maximal suppression (62.2% as compared with 49.6% for free prednisolone) was observed even at a minimal dose (2.5 mg/kg), at which the free drug did not act at all. The results indicate an increase in the efficiency of prednisolone included in phospholipid nanoparticles, that makes it possible to diminish its administered doses and thereby reduce the risk of side effects.

[Interaction of rifampicin embedded in phospholipid nanoparticles with blood plasma lipoproteins].

The drug formulations of antituberculous remedy rifampicin in nanoparticles less than 30 nm based on soy phosphatidylcholine and sodium oleate was elaborated in Institute of Biomedical Chemistry. The distribution of rifampicin in blood plasma fractions after incubation with this formulation and with free rifampicin was studied. This goal was stimulated by the literature data about activation of macrophages LDL receptors in cases of M. tuberculosis infection. Plasma was incubated 30 min with free rifampicin or rifampicin encapsulated into the nanoformulation followed by ultracentrifugation and subsequent rifampicin determination by HPLC in lipoprotein fractions. In the case of free rifampicin it appeared mainly in the plasma protein fraction and in HDL (41% and 38%, correspondentely). But after incubation of rifampicin in nanoparticles the drug redistribution was observed. Its proportion in these factions decreased 2-3-fold, and it was found mainly in LDL (60% as compared with 21% for free rifampicin). The increased association of rifampicin encapsulated into phospholipid nanoparticles with LDL is considered as facilitating factor for macrophages delivery and thus for antituberculosis efficiency as well.

[Development of targeted drug delivery system: synthesis of conjugates of address fragment (RA-COOH) with ligand (R-NH2)].

One of the main ways to increase the effectiveness of well-known medical formulations well-established in clinical medicine - development of delivery systems using new technological approaches and nanomaterials. Currently, much attention is given to targeted delivery systems. At the same time drug carrier has in addition to medication the so-called vector/address with a high affinity for binding to specific receptors on cells/tissue target. In this paper it is described the method for producing of address conjugates to over-expressed receptors on the tumor cells. As address fragment it was folic acid and as a linker was dodecylamine, causing inclusion the conjugate into lipid nanoparticles.

[Nanoparticles as drug delivery system for antituberculous drugs].

The increase of tuberculosis incidence in last decade stimulated elaboration of both new antituberculous drugs and also searches ofoptimiting delivery systems for existing drugs. It is determined by their side effects and low bioavailability of effective first line drug rifampicin. Various nanosystems for transport of antituberculous drugs are considered on the basis of various polymers, liposomes, lipid nanoparticles, nanoemulsios, nanosuspensions, dendrimers, cyclodextrines. Influence of drug incorporation into nanoparticles, most often for rifampicin, on pharmacokinetics and efficiency in tuberculosis models is discussed. The most of works are devoted to polymer nanoparticles for oral administration where increased circulation time and efficiency were shown. The best results were observed after drug inclusion into solid lipid nanoparticles. The liposomes formulations were investigated mostly for inhalation and injection administrations. Positive results were also observed. Authors underline the viability of incorporation of antituberculous drugs into phospholipid nanoparticles that may increase intestinal absorption and bioavailability. It is confirmed by authors' own data that showed increase of rifampicin efficiency after their incorporation into such nanoparticles.

[Drug delivery system on the base of phospholipid nanoparticles for rifampicin].

Low bioavailability of rifampicin, one of the main antituberculous drug, stimulates searches of its new optimized formulations. The present study has showen possibility of rifampicin embedding into nanoparticles from plant phosphatidylcholine (diameter of 20-30 nm). Addition of sodium oleate to the phospholipid system caused a 2-fold increase of the percent of rifampicin incorporation. After oral administration to rats, the maximal drug observed in plasma one hour after was 0.5 and 4.2 mkg/ml for free rifampicin for rifampicin in phospholipids-oleate nanoparticles, respectively. These levels were maintained for more than two hours of the experiment. High rifampicin bioavailability in the oleate containing phospholipid nanosystem suggests prospectivity of its pharmaceutical elaboration.

[The absorption features of glycyrrhizic acid in composition of drug "phosphogliv"].

Glycyrrhizic acid (GL)--one of the active components of the Russian drug formulation "Phosphogliv" possesses extremely low bioavailability. A sensitive method for GL determination in blood using high performance liquid chromatography coupled with mass-spectrometry (HPLC-MS) has been developed in order to investigate absorption characteristics of glycyrrhizic acid after peroral administration of "Phosphogliv" and GL sodium salt. Separation of blood components was achieved on the analytical reverse-phase column C18 "EcoNova" ProntoSIL, using a gradient mode. Detection of GL and an internal standard (IS) (glycyrrhetic acid) was performed using electrospray ionization with the selected ion monitoring in negative mode (SIM) using target ions at m/z 821.3 for GL and 469.3 for IS. The calibration curve was linear over the range of 50-5000 ng/ml (the correlation coefficient was 0.995). The detection limit for GL in blood was 25 ng/ml and the lower limit of quantification was 50 ng/ml. The developed method has been applied to compare absorption efficiency of glycyrrhizic acid as the component of "Phosphogliv" composition and solution of GL sodium salt during first two hours after their single peroral administration to rats at the dose of 8.5 mg/kg. It was shown that GL absorption occurs several minutes after peroral administration. Moreover, GL bioavailability after administration of drug "Phosphogliv" was higher than after administration of GL sodium salt. This difference may be attributed to incorporation of glycyrrhizic acid in the phospholipid nanoparticles structure.

Influence of doxorubicin inclusion into phospholipid nanoformulation on its antitumor activity in mice: increased efficiency for resistant tumor model.

AIM: The new formulation of doxorubicin on the base of phospholipid nanoparticles (particle size <30 nm) is elaborated in the Institute of Biomedical Chemistry (Russian Academy of Medical Sciences) on the base of plant phospholipids. The aim of study is to investigate an antitumor effect of this nanoformulation in mice with two cancer models with various sensitivity to chemotherapy ­ lymphoid malignancy P-388 and Lewis lung carcinoma (LLC). METHODS: Nanophospholipid (NPh) formulation of doxorubicin was prepared by homogenization of soybean phosphatidylcholine and doxorubicin hydrochloride. The effect of this formulation was studied in experiments with single or threefold drug administration. Percents of tumor growth inhibition in mice under influence of free or NPh doxorubicin forms were compared. RESULTS: Single administration of both free and NPh doxorubicin in mice with P-388 resulted in the same quick severe inhibition of tumor growth (60­90% depending from dose), with further gradual decrease of inhibition degree. However for more resistant tumor, LLC, the obvious advantage of NPh doxorubicin form was shown. The little effect of free doxorubicin began to reveal only after 11 days, but NPh formulation induced significant inhibition of tumor growth (40%) from the first experimental point (6 days after administration). The advantages of NPh doxorubicin was manifested particularly in low drug doses, 2 and 4 mg/kg. In other experiment design in mice with LLC, with threefold weekly drug administration, NPh doxorubicin appeared to be 2.5 times more active than free drug. The reason of the same actions of free and NPh doxorubicin form in P-388 is suggested the high drug sensitivity of this model, that gives quick high drug response for any doxorubicin form. CONCLUSION: Doxorubicin in phospholipids nanoformulation revealed higher antitumor efficiency as compared with free doxorubicin in mice with LLC carcinoma. The mechanism of such changes is supposed to be caused by increase of doxorubicin availability for cancer cells.

[Changes of doxorubicin distribution in blood and plasma after its inclusion into nanophospholipd formulation].

The drug composition based on the plant phospholipids and the antitumor drug doxorubicin (particle size <30 nm) was obtained using original technology elaborated in the Institute of Biomedical Chemistry (Russian Academy of Medical Sciences). In in vitro experiments demonstrated decreased drug association with blood cells for this nanophospholipid form as compared with free doxorubicin. This was accompanied by a with corresponding increase in its plasma level ans also by drug redistribution from plasma protein fraction to high density lipoproteins. Significance of these changes for doxorubicin biodistributon and antitumor activity is discussed.

[The increase of bioavailability and anti-inflammatory effect of indomethacin loaded into phospholipid nanoparticles].

The ultrafine formulation on the base of plant phosphatidylcholine and antiinflammatory remedy indomethacin with nanoparticles less than 50 nm was obtained. Drug bioavailability after its peroral administration to rats was more than 2 fold higher as compared with free indomethacin. Increased antiinflammatory activity of indomethacin in phospholipids nanoparticles as compared with its free form was shown in two models of inflammation - adjuvant arthritis in rats and conconavalin A induced edema in mice. The increased bioavailability of indomethacin after administration of its phospholipid formulation allows to decrease a dose for achievement of therapeutic effect, that reduces risks of occurrence of collateral displays.

[Bioavailability of oral drug formulations and methods for its improvement].

The recent studies in nanotechnology resulted in the development of novel formulations with improved bioavailability. This is especially important for oral administered drugs as the most convenient formulations. The current review deals with the processes occurring at the gastro-intestinal (GI) tract and their influence on the drug form. The increase of bioavailability of the drug may be achieved through designing novel formulations according to the specific drug properties. They include capsules that release pharmaceutical agents at various parts of the GI tract, floating systems that prolong the presence of the drug in the GI tract, dispersed forms with surface-active soluble polymers, micelles that carry poor-soluble drugs inside their non-polar core, agents that facilitate tight junction opening, such as caprate and chitosan, and lipid-based formulations. The own data show the stimulating influence of phospholipid nanoparticles on peroral absorption of drug indomethacin in rats and on passage of transport marker and drugs through Caco-2 cell monolayer in vitro. The review summarizes current understanding of factors that influence the bioavailability of the oral drug forms, currently used models for pharmacokinetic studies, and various approaches to developing novel pharmaceutical forms that increase the bioavailability of the drugs.

Study of interaction of ceruloplasmin, lactoferrin, and myeloperoxidase by photon correlation spectroscopy.

In this work, the diameters of protein complexes formed upon interaction of ceruloplasmin (CP) with lactoferrin (LF) and myeloperoxidase (MPO) were determined. Gage dependence of the diameter of protein particles (myoglobin, albumin, LF, CP, MPO, aldolase, ferritin) on their molecular mass logarithm was calculated. The diameter of a complex formed upon mixing CP and LF was 8.4 nm, which is in line with the radius of gyration obtained previously when the 1CP-1LF complex was studied by small-angle X-ray scattering. The diameter of a complex formed upon interaction of CP with MPO is 9.8 nm, corresponding to the stoichiometry 2CP : 1MPO. The diameter of a complex formed when LF is added to the 2CP-1MPO complex is 10.7 nm. The latter is consistent with the notion of a pentameric structure 2LF-2CP-1MPO with molecular mass of about 585 kDa.

[Possibilities for use of phospholipid nanosystem with glycyrrhizic acid ("phosphogliv") for optimization of drugs: doxorubicin and budesonide as examples].

The complexes of phospholipids nanoparticles (as the injection form of newly developed hepatoprotector phosphogliv) with the antitumor drug doxorubicin or with glucocorticoid budesonide have been investigated for their pharmacological activity in comparison with free forms of these drugs. Doxorubicin with phosphogliv revealed more antitumor and antimetastatic activity in C47B 1/6 mice with carcinoma LLC than free doxorubicin. Inhalation of budesonide with phosphogliv in vivo to quinea pigs resulted to more pronounced decrease of antigen or histamin induced bronchospasm, particularly its subacute phase, as compared with traditional powder or suspension budesonide forms. This suggests that the phosphogliv injection forms may be used not only for treatment of liver diseases, but also for delivery of a number of other drugs and consequently for optimization of their efficiency.

[Antirheumatoid activity of methotrexate in phospholipid nanoparticles (Phosphogliv)].

The efficiency of methotrexate use in basic therapy of rheumatoid arthritis is limited because of risk of side effects and fast drug efflux from zone of joints as well. The new stabilized form of methotrexate was elaborated with phospholipid micelles as a carrier. The injective form of the preparation Phosphogliv was used for this purpose. Phosphogliv has recently been developed in the Institute of Biomedical Chemistry (Moscow), as the emulsion of 50 nm phospholipid nanoparticles stabilized by glycyrrhizic acid. The conditions of maximal methotrexate incorporation into the phospholipid nanoparticles were optimised under control of HPLC (60% of total methotrexate was associated with nanoparticles, with remaining drug being in free form in the water phase). Such preparation revealed higher therapeutic efficiency in experimental adjuvant arthritis in rats as compared with free methotrexate. The increase of antirheumatoid activity of the elaborated preparation may also be attributed to the influence of glycyrrhizic acid, possessing both antiinflammatory and immune properties. The possibility of clinical employment of a new methotrexate drug form for rheumatoid arthritis treatment is discussed.

[Study of substrate specificity of a new peptide substrate of endothelin converting enzyme].

The new fluorogenic hexapeptide substrate CMC-Ala-Gly-Gly-Trp-Phe-Arg was used as substrate for endothelin-converting enzyme (ECE), angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The specific inhibitors lisinopril (ACE) and thiorphan (NEP) were used for identification of these enzyme activities,

[Peculiarity of the antioxidant action of the extract from Aronia melanocarpa leaves antioxidant on the brain].

The antioxidant action of the extract from Aronia melanocarpa leaves on the brain was investigated. The intraperitoneal injection of extract in the dose of 0.2 g/kg prevented manifestations of oxidative stress in the brain induced by immobilization of rats. In vitro experiments revealed that the extract decreased intensity of ascorbate--and H2O2 -induced lipid and protein peroxidation in the brain homogenates. The most effect of the extract on ascorbate--induced lipid peroxidation was found in the postmitochondrial fraction of brain homogenate.

[Antioxidant properties of a leaf extract from Aronia (Aronia melanocarba) containing proanthocyanidins]. / Antioksidantnye svoistva ékstrakta list'ev aronii (Aronia melanocarpa), soderzhashchego proantotsianidininy.

Antioxidant capacity of a procyanidin-containing extract from Aronia melanocarpa leaves has been studied in vitro and in vivo. Using the chemiluminescence technique, the effective content of antioxidants and its reactivity towards peroxyl radicals have been measured in a model reaction of initiated oxidation of hydrocarbon for the whole extract and two of its chromatographic fractions separated by HPLC. The results indicate that the extract contains a combination of antioxidants with different radical scavenging activities. The value of the rate constant of the reaction with peroxyl radicals (constant k7) for the extract strong inhibitors is of the same order of that for alpha-tocopherol and its synthetic analog chroman C. A decrease in antiradical activity directly related to the high concentrations of this extract in reactive mixture has been observed. This extract significantly reduced in dose-dependent fashion the CCl4-induced hepatic lipid peroxidation. The extract also inhibited flaxseed oil peroxidation. The present study indicates significant antioxidant capacity of the extract from Aronia melanocarpa leaves.

[Structural and functional characteristics of insulin and mechanism of its effect]. / Strukturno-funktsional'nye osobennosti insulina i mekhanizma ego deistviia.

On the basis of analysis of own and literature data on insulin-receptor interaction two centers responsible for receptor binding were identified on 3D-structure of insulin with receptor. Two extracellular domains of insulin receptor interact with these centers on insulin molecule. The comparative analysis of primary structures of the protein disulfide isomerase thioredoxine domains and C-terminal domain of the receptor suggests existence of the thioredoxine domain in the insulin receptor. In this connection the role of the thiol disulfide an exchange reaction is discussed in terms of insulin interaction with receptor followed by subsequent conformational changes in the receptor molecule and activation of the intercellular tyrosine kinase domain. It is supposed, that besides known mechanism of receptor mediated insulin signal transduction and tyrosine kinase activation, there is other mechanism of insulin intracellular signal transduction realised via cytosolic insulin-binding proteins. Major components of intercellular insulin signal transduction include: protein disulfide isomerase and insulin degrading enzyme. The importance of change of the intracellular insulin degradation rate for insulin signal transduction is discussed.

[Hypoglycemic effect of an extract from Aronia melanocarpa leaves]. / Issledovanie gipoglikemicheskogo deistviia ékstrakta iz list'ev Aronia melanocarpa.

The action of extract from Aronia melanocarpa leaves to blood glucose level was investigated. It was shown that incorporated into drinking water and administrated intraperitoneally, the extract significantly reduce the blood glucose level of streptozotocin (STZ)-diabetic and normal rats.

[Stimulation of glucose uptake in PC 12 and L 929 cells by extracts from Aronia melanocarpa leaves]. / Stimuliatsiia pogloshcheniia gliukozy kletkami PC 12 i L 929 ékstraktom iz list'iev Aronia melanocarpa.

The ability of extract from Aronia melanocarpa leaves to increase glucose uptake was investigated. It was shown, that the extract stimulated glucose uptake by cells PC12 and L 929 at the concentration close to native insulin.