Nanoliposomes as drug delivery systems: safety concerns.

The review highlights the safety issues of drug delivery systems based on liposomes. Due to their small sizes (about 80-120 nm, sometimes even smaller), phospholipid nanoparticles interact intensively with living systems during parenteral administration. This interaction significantly affects both their transport role and safety; therefore, special attention is paid to these issues. The review summarises the data on the basic factors affecting the safety of nanoliposomes: composition, size, surface charge, stability, the release of an incorporated drug, penetration into tissues, interaction with the complement system. Attention is paid to the authors' own research of unique phospholipid nanoparticles with a diameter of 20-30 nm. The influence of technological processes of nanoliposome production on their properties is considered. The article also discusses the modern safety assessment criteria contained in the preliminary regulatory documents of the manufacturing countries for new nanoliposome-based drugs being developed or used in the clinic.

[The effect of lipid derivative of anti-tumor drug sarcolysin embedded in phospholipid nanoparticles in the experiments in vivo]. / Deistvie lipidnogo proizvodnogo protivoopukholevogo lekarstva sarkolizina, vkliuchennogo v fosfolipidnye nanochastitsy, na opukholi v éksperimentakh in vivo.

To improve the therapeutic properties of the antitumor agent Sarcolysin, we have previously developed and characterized a dosage form representing its ester conjugate with decanol embedded in ultra-small phospholipid nanoparticles less than 30 nm in size ("Sarcolysin-NP"). The effect of the resulting composition was investigated in vivo in comparison with the free substance of sarcolysin. The composition intravenous administration to mice showed an improvement in the pharmacokinetic parameters of sarcolysin associated with its initial higher (by 22%) level in the blood and prolonged circulation, which was also observed in mice with P388 tumor. In mice with three types of tumors - lymphocytic leukemia P388, lymphocytic leukemia L1210, and adenocarcinoma of the mammary gland Ca755 - administration of two doses of sarcolysin over a period of 7 days showed its predominant antitumor effect. The maximum tumor growth inhibition was noted for lymphocytic leukemia L1210 and adenocarcinoma of the mouse mammary gland Ca755 (at a dose of Sarcolysin-NP - 8,4 mg/kg), which was higher in comparison with free substance by more than 24% and 17%, respectively. Differences in the life span of the treated animals were revealed significantly at a dose of 10 mg/kg and amounted to 25% and 17,4% for lymphocytic leukemia P388 and L1210, respectively, and 11% for adenocarcinoma Ca755. In an experiment on rats, acute toxicity of Sarcolysin-NP administered intravenously showed that an average LD50 value 2-3 times exceeded a similar parameter for commercial preparations of free sarcolysin (Melphalan and Alkeran), which indicates its lower toxicity.

Composite phospholipid-gold nanoparticles with targeted fragment for tumor imaging.

Gold nanoparticles and their conjugates have significant potential in the field of diagnosis of various diseases due to their SPR, which enhances light scattering and absorption. Conjugates of gold nanoparticles with various ligands can be used for imaging biomolecules or detecting malignant neoplasms at an early stage. This study focuses on the construction of composite (or hybrid) phospholipid-gold nanoparticles using soy phosphatidylcholine and a targeted ligand (folic acid derivative) to attach specific targeting properties. According to the method of dynamic light scattering, the diameter of the obtained nanoparticles was less than 100 nm, the results of the MTT test indicated their moderate cytotoxicity. In vitro and in vivo experiments showed a significant increase in the accumulation of phospholipid-gold nanoparticles with a targeted fragment compared to those without a targeted fragment both in HeLa cells and in a tumor (in BDF mice with an injected LLC tumor). The resulting nanoparticles are suitable for specific delivery into tumor cells and visualization of various malignant neoplasms, including at early stages, due to the increased expression of the folate receptor characteristic of cells of a wide range of tumors.

[Plasma high density lipoproteins phospholipds as an indirect indicator of their cholesterol efflux capacity - new suspected atherosclerosis risk factor]. / Uroven' fosfolipidov lipoproteinov vysokoi plotnosti plazmy kak kosvennyi pokazatel' ikh kholesterin-aktseptiruiushchei sposobnosti.

High density lipoproteins (HDL) are a unique natural structure, protecting the body from the development of atherosclerotic vascular lesions and cardiovascular diseases due to this ability to remove cholesterol from cells. Plasma HDL level estimated by their cholesterol content, is a common lipid parameter, and its decrease is considered as an established atherosclerosis risk factor. However, a number of studies have shown the absence of positive clinical effects after drug-induced increase in HDL cholesterol. There is increasing evidence that not only HDL concentration, but also HDL properties, considered in this review are important. Many studies showed the decrease of HDL cholesterol efflux capacity in patients with coronary heart diseases and its association with disease severity. Some authors consider a decrease of this HDL capacity as a new additional risk factor of atherosclerosis. The review summarizes existing information on various protein and lipid components of HDL with a primary emphasis on the HDL. Special attention is paid to correlation between the HDL cholesterol efflux capacity and HDL phospholipids and the ratio "phospholipids/free cholesterol". The accumulated information indicates importance of evaluation in the HDL fraction not only in terms of their cholesterol, but also phospholipids. In addition to the traditionally used lipid criteria, this would provide more comprehensive information about the activity of the reverse cholesterol transport process in the body and could contribute to the targeted correction of the detected disorders.

[Targeted drug delivery system for doxorubicin based on a specific peptide and phospholipid nanoparticles]. / Sistema adresnoi dostavki dlia doksorubitsina na osnove spetsificheskogo peptida i fosfolipidnykh nanochastits.

Doxorubicin is one of the widely known and frequently used chemotherapy drugs for the treatment of various types of cancer, the use of which is difficult due to its high cardiotoxicity. Targeted drug delivery systems are being developed to reduce side effects. One of the promising components as vector molecules (ligands) are NGR-containing peptides that are affinity for the CD13 receptor, which is expressed on the surface of many tumor cells and tumor blood vessels. Previously, a method was developed for preparing a composition of doxorubicin embedded in phospholipid nanoparticles with a targeted fragment in the form of an ultrafine emulsion. The resulting composition was characterized by a small particle size (less than 40 nm) and a high degree of incorporation of doxorubicin (about 93%) into transport nanoparticles. When assessing the penetrating ability and the degree of binding to the surface of fibrosarcoma cells (HT-1080), it was shown that when the composition with the targeted fragment was added to the cells, the level of doxorubicin was almost 2 times higher than that of the liposomal form of doxorubicin, i.e. the drug in the system with the targeted peptide penetrated the cell better. At the same time, on the control line of breast adenocarcinoma cells (MCF-7), which do not express the CD13 receptor on the surface, there was not significant difference in the level of doxorubicin in the cells. The data obtained allow us to draw preliminary conclusions about the prospects of targeted delivery of doxorubicin to tumor cells when using a peptide conjugate containing an NGR motif and the further need for its comprehensive study.

The Role of Halogenative Stress in Atherogenic Modification of Low-Density Lipoproteins.

This review discusses formation of reactive halogen species (RHS) catalyzed by myeloperoxidase (MPO), an enzyme mostly present in leukocytes. An imbalance between the RHS production and body's ability to remove or neutralize them leads to the development of halogenative stress. RHS reactions with proteins, lipids, carbohydrates, and antioxidants in the content of low-density lipoproteins (LDLs) of the human blood are described. MPO binds site-specifically to the LDL surface and modifies LDL properties and structural organization, which leads to the LDL conversion into proatherogenic forms captured by monocytes/macrophages, which causes accumulation of cholesterol and its esters in these cells and their transformation into foam cells, the basis of atherosclerotic plaques. The review describes the biomarkers of MPO enzymatic activity and halogenative stress, as well as the involvement of the latter in the development of atherosclerosis.

[Chlorine e6 in phospholipid nanoparticles with specific targeting and penetrating peptides as prospective composition for photodynamic therapy of malignant neoplasms]. / Khlorin e6 v fosfolipidnykh nanochastitsakh so spetsificheskimi adresnymi i pronikaiushchimi peptidami kak perspektivnaia kompozitsiia dlia fotodinamicheskoi terapii zlokachestvennykh novoobrazovanii.

Cytotoxic and photoinduced activity of chlorine e6 (Ce6) in phospholipid nanoparticles with specific tumor targeting and cell-penetrating peptides was studied in vitro using human fibrosarcoma cells HT-1080. It was shown, that the binding of cell-penetrating peptide R7 - alone or combined with the peptide containing specific targeting motif NGR (Asn-Gly-Arg) - resulted in 3-fold decrease of Ce6 photoinduced activity as compared with that in nanoparticles without peptides (IC50 values were 0.7 µg/ml and 2.1 µg/ml, respectively). The NGR influence was unexpectedly low - less than 20% (IC50 1.7 µg/ml). This suggests the more importance of Ce6 cell penetration in this case, than of NGR-mediated targeting. The effect of inclusion of both peptides on the total cytotoxicity of Ce6 was minimal (10-16 times less than on the specific photoinduced activity). The obtained results - together with earlier shown effects on improvement of the pharmacokinetics of Ce6 in vivo after its embedding into phospholipid nanoparticles - indicate the prospects of using the obtained phospholipid nanoparticles system for photodynamic therapy.

[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.

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.

[Improving of HDL capacity for macrophages cholesterol efflux after plasma incubation with phospholipid nanoparticles]. / Povyshenie sposobnosti lipoproteinov vysokoi plotnosti k vyvedeniiu kholesterina iz makrofagov pri inkubatsii plazmy s ul'tramalymi fosfolipidnymi chastitsami.

In connection with recent data about antiatherogenic importance of not only plasma HDL concentration, but of their cell cholesterol efflux capacity as well, the possibility of its correction by phospholipid (PL) nanoparticles was studied. Blood plasma was incubated with earlier elaborated PL nanoparticles emulsion with the particle diameter up to 30 nm, and HDL cholesterol efflux capacity of apo B-depleted plasma was studied. Using macrophages THP-1 preloaded 3H-cholesterol were used. The addition of incubated plasma supernatants with the elevated PL/apo A-1 ratio to cell media resulted in almost increase in two fold 3H-cholesterol efflux as compared with native HDL. The maximal efflux was observed at the PL/apo A-1 ratio of 1.06 as compared with native apo B-depleted plasma (the PL/apo A-1 ratio of 0.85). Results suggest possible usage of ultrasmall PL nanoparticles for regeneration of impaired antiatherogenic HDL functionality. This approach seems to be predominant compared with the usage of PL emulsions with detergent or apoprotein A1.

[Pharmacological targets for dislipidemies correction. Opportunities and prospects of therapeutic usage]. / Farmakologicheskie misheni korrektsii dislipidemii. Vozmozhnosti i perspektivy terapevticheskogo ispol'zovaniia.

Literature data on influence of existing and new groups of drug preparations for dyslipidemias correction are systemized, and molecular mechanisms of their effects are reviewed. The results of experimental and clinical investigations aimed at revealing of new pharmacological targets of dyslipidemias correction were analyzed. The approaches for activation of high density lipoproteins functionality are described. The implementation of alternative preparations with new alternative mechanisms of action may be suggested to improve the effectiveness of traditional treatment in the future.

[Increase of antituberculosis efficiency of rifampicin embedded into phospholipid nanoparticles with sodium oleate]. / Povyshenie protivotuberkuleznogo deistviia rifampitsina pri vstraivanii v fosfolipidnye nanochastitsy c oleatom natriia.

The formulation of the antituberculosis drug rifampicin embedded into 20-30 nm nanoparticles from soy phosphatidylcholine and sodium oleate, is characterized by greater bioavailability as compared with free drug substance. In this study higher antituberculosis activity of this formulation was shown. Rifampicin in nanoparticles demonstrated more effective inhibition of M. tuberculosis H37Rv growth: minimal inhibiting concentration (MIC) was twice smaller than for free rifampicin. Administration of this preparation to mice with tuberculosis induced by M. tuberculosis Erdman revealed that after 6 weeks of oral administration the CUF value in lung was 22 times smaller for rifampicin in nanoparticles than for free drug (1.7 un. vs. 37.4 un.). The LD50 value in mice was two fold higher for rifampicin in nanoformulation.

[Influence of doxorubicin inclusion into phospholipid nanoparticles on tumor accumulation and specific activity]. / Vliianie vkliucheniia doksorubitsina v fosfolipidnye nanochastitsy na nakoplenie v opukholi i spetsificheskuiu aktivnost'.

The specific activity of drug formulation of doxorubicin embedded into phospholipid nanoparticles with diameter less than 30 nm ("Doxolip") was studied in mice LLC carcinoma. Doxolip was prepared according to technology that was elaborated in Institute earlier. Doxorubicin tumor accumulation after intraperitoneal administration (at 4 h) was 4.5 times higher for Doxolip, than for free doxorubicin. The study of doxorubicin antitumor activity in developing tumor after single intravenous administration, 48 h after inoculation, showed, that: 1) tumor growth inhibition of Doxolip was observed at 6th day, while it was only at 11th day for free doxorubicin and revealed in less extent; 2) there was no antitumor effect of free doxorubicin at 8 days after administration of doses 2 and 4 mg/kg, but it was observed for Doxolip in dose-dependent manner, 10% and 30% correspondently. In experiment with developed tumor weekly Doxolip intraperitoneal administration (5 mg/kg, 3 weeks beginning from 7 days after inoculation) resulted in 56% decrease of tumor volume as compared with control. This parameter for free doxorubicin was 2.8 times lower. The obtained data indicate, that incorporation of doxorubicin into phospholipid nanoparticles with size up to 30 nm as delivery system increases its tumor accumulation and results to increase of specific activity both in intraperitoneal and in intravenous administration.

[Investigation of efficacy of phospholipovit for correction of the hepatic encephalopathy]. / Issledovanie éffektivnosti preparata fosfolipovit dlia korrektsii pechenochnoi éntsefalopatii.

This paper presents the results of clinical studies on the efficacy and safety of the drug Phospholipovit in different groups of patients, in particular with hepatic encephalopathy and with a high risk of its development (chronic alcohol intoxication). Efficacy of treatmernt was evaluated by the LNT test (link numbers test), and standard liver plasma markers (ALT, AST, GGT, AP). The LNT test in patients with encephalopathy showed better improvement after 5 days course of Phos-pholipovit than after standard therapy. In both clinical trials liver enzyme activities, assayed in pa-tients declined more rapidly in the group of patients treated with Phospholipovit, as compared in patients received standard therapy alone. The highest clinical effect of the drug on the liver function tests was observed at a daily dose of 6.4 g of phospholipids (infusional 2 times a day) for 5-10 days. At the end of treatment a two-fold decrease in the activity of AST was observed in patients receiv-ing Phospholipovit compared to the control. This results of clinical results can be regarded as a manifestation of the expressed membrane repairing action of essential phospholipids, reinforced by their introduction into the body in the form of nanoparticles.

[Influence of resveratrol and dihydroquercetin inclusion into phospholipid nanopatricles on their bioavailability and specific activity].

The effects of natural polyphenols, resveratrol (RES) and dihydroquercetin (DHQ), included in phospholipid nanoparticles, have been compared with free substances of RES and DHQ in in vitro and in vivo experiments. Preincubation of healthy donor plasma low density lipoproteins (LDL) with RES or DHQ included in phospholipid nanoparticles caused a more pronounced decrease in Cu2+ induced lipid oxidation compared with the free substances, and reduced the formation of lipid peroxides products. Bioavailabilities of RES and DHQ in phospholipid formulations after oral administration in rats were increased by 1.5-2 times. In an acute hypoxia model in mice prophylactic two-week administration of RES or DHQ phospholipid formulations resulted in 25% increase in survival and 1.5-fold increase in catalase activity in brain homogenates compared to free substances. Using the model of endothelial dysfunction in rats induced by L-NAME it was shown, that RES markedly attenuated the inhibition effect of L-NAME on NO synthesis. RES in phospholipid nanoparticles had the same action at a dose 10 times lower compared to free RES. Load test with resistance (clamping of the ascending aorta for 30 sec) showed that phospholipid formulation of RES possessed more pronounced protective effect due to the stimulation of endothelial NO-synthase.

[The influence of doxorubicin incorporated in phospholipid drug delivery nanosystem on HEPG2 cells proteome].

A phospholipid drug delivery nanosystem with particle size up to 30 nm elaborated at the Institute of Biomedical Chemistry has been used earlier for incorporation of doxorubicin (Doxolip). This system demonstrated higher antitumor effect in vivo as compared with free doxorubicin. In this study the effect of this nanosystem containing doxorubicin on HepG2 cell proteome has been investigated. Cells were incubated in a medium containing phospholipid nanoparticles (0.5 mg/ml doxorubicin, 10 mg/mL phosphatidylcholine). After incubation for 48 h their survival represented 10% as compared with untreated cells. Cell proteins were analyzed by quantitative two-dimensional gel electrophoresis followed by identification of differentially expressed proteins with MALDI-TOF mass spectrometry. The phospholipid transport nanosystem itself insignificantly influenced the cell proteome thus confirming previous data on its safety. Doxorubicin, as both free substance and Doxolip (i.e. included into phospholipid nanoparticles) induced changes in expression of 28 proteins. Among these proteins only four of them demonstrated different in response to the effect of the free drug substance and Doxolip. Doxolip exhibited a more pronounced effect on expression of certain proteins; the latter indirectly implies increased penetration of the drug substance (included into nanoparticles) into the tumor cells. Increased antitumor activity of doxorubicin included into phospholipid nanoparticles may be associated with more active increase of specific protein expression.

[Mass spectrometry analysis of blood plasma lipidome as method of disease diagnostics, evuation of effectiveness and optimization of drug therapy].

A new method for the analysis of blood lipid based on direct mass spectrometry of lipophilic low molecular weight fraction of blood plasma has been considered. Such technique allows quantification of hundreds of various types of lipids and this changes existing concepts on diagnostics of lipid disorders and related diseases. The versatility and quickness of the method significantly simplify its wide use. This method is applicable for diagnostics of atherosclerosis, diabetes, cancer and other diseases. Detalization of plasma lipid composition at the molecular level by means of mass spectrometry allows to assess the effectiveness of therapy and to optimize the drug treatment of cardiovascular diseases by phospholipid preparations.

[Neuropeptides, Cytokines and Thymus Peptides as Effectors of Interactions Between Thymus and Neuroendocrine System].

The review presents data on mutual influence of nervous system and thymus, realized through the neuroendocrine-immune interactions. The pres- ence of adrenergic and peptidergic nerves in thymus creates conditions for implementation of the effect of neuropeptides secreted by them. These neuropeptides induce activation of thymus cells receptors and influence on the main processes in thymus, including T-lymphocyte maturation, cytokine and hormones production. In turn, thymuspeptides and/or cytokines, controlled by them, enter the brain and exert influence on neuro- nalfunction, which creates the basis for changes of behavior and homeostasis maintenance in response to infection. Ageing and some infectious, autoimmune, neurodegenerative and cancer diseases are accompanied by distortion of interactions between thymus and central nervous system. Mechanisms of signaling pathways, which determine these interactions, are not revealed yet, and their understanding will promote the development of effective therapeutic strategies.

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.

Lysophospholipid receptors in cell signaling.

There is increasing evidence that different phospholipids are involved in regulation of various cell processes and cell-cell interactions. Lysophospholipids (lysophosphatidic acid, lysophosphatidylcholine) and a number of lysosphingolipids play particular roles in these regulations. Their effects are mediated by specific G-protein-coupled receptors. G-Protein coupled signal transduction to the cell nucleus involving a chain of intracellular protein kinases induces the main effects in cells--growth, proliferation, survival, or apoptosis. This review summarizes recent data on various groups of lysophospholipid receptors and their cell signal transduction pathways.