A dual-vector phospholipid nanosystem of doxorubicin: accumulation and cytotoxic effect in breast cancer cells in vitro.

Various chemotherapeutic agents are used to treat breast cancer (BC); one of them is the anthracycline antibiotic doxorubicin (Dox), which, in addition to its cytostatic effect, has serious side effects. In order to reduce its negative impact on healthy organs and tissues and to increase its accumulation in tumors, Dox was incorporated into phospholipid nanoparticles. The additional use of vector molecules for targeted delivery to specific targets can increase the effectiveness of Dox due to higher accumulation of the active substance in the tumor tissue. The integrin αvß3, which plays an important role in cancer angiogenesis, and the folic acid receptor, which is responsible for cell differentiation and proliferation, have been considered in this study as targets for such vector molecules. Thus, a phospholipid composition of Dox containing two vector ligands, cRGD peptide and folic acid (NPh-Dox-cRGD-Fol(3,4)), was prepared. Study of the physical properties of the developed composition NPh-Dox-cRGD-Fol(3,4) showed that the average particle size was 39.62±4.61 nm, the ζ-potential value was 4.17±0.83 mV. Almost all Dox molecules were incorporated into phospholipid nanoparticles (99.85±0.21%). The simultaneous use of two vectors in the composition led to an increase in the Dox accumulation in MDA-MB-231 BC cells by almost 20% as compared to compositions containing each vector separately (folic acid or the cRGD peptide). Moreover, the degree of Dox internalization was 22% and 24% higher than in the case of separate use of folic acid and cRGD peptide, respectively. The cytotoxic effect on MDA-MB-231 cells was higher during incubations with the compositions containing folic acid as a single vector (NPh-Dox-Fol(3,4)) and together with the RGD peptide (NPh-Dox-cRGD-Fol(3,4)). Experiments on the Wi-38 diploid fibroblast cell line have shown a significantly lower degree of cytotoxic effect of the phospholipid composition, regardless of the presence of the vector molecules in it, as compared to free Dox. The results obtained indicate the potential of using two vectors in one phospholipid composition for targeted delivery of Dox.

[Study of the efficiency of cellular accumulation of doxorubicin supplied with a targeted delivery system based on phospholipid nanoparticles with integrin-directed peptide]. / Issledovanie éffektivnosti kletochnogo nakopleniia doksorubitsina, snabzhennogo targetnoi sistemoi dostavki na osnove fosfolipidnykh nanochastits c integrin-napravlennym peptidom.

Chemotherapeutic agents containing targeted systems are a promising pathway to increase the effectiveness of glioblastoma treatment. Specific proteins characterized by increased expression on the surface of tumor cells are considered as possible targets. Integrin αvß3 is one of such proteins on the cell surface. It effectively binds the cyclic Arg-Gly-Asp (cRGD) peptide. In this study, the cRGD peptide-modified doxorubicin (Dox) phospholipid composition was investigated. The particle size of this composition was 43.76±2.09 nm, the ζ-potential was 4.33±0.54 mV. Dox was almost completely incorporated into the nanoparticles (99.7±0.58%). The drug release increased in an acidic medium (at pH 5.0 of about 35±3.2%). The total accumulation and internalization of Dox used the composition of phospholipid nanoparticles with the targeted vector was 1.4-fold higher as compared to the free form. In the HeLa cell line (not expressing αvß3 integrin) this effect was not observed. These results suggest the prospects of using the cyclic RGD peptide in the delivery of Dox to glioblastoma cells and the feasibility of further investigation of the mechanism of action of the entire composition as a whole.

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.

[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.

Preclinical Study of Pharmacological Properties of Doxorubicin-NPh.

Preclinical study of therapeutic properties of an innovative drug Doxorubicin-NPh (doxorubicin in the form of ultrafine suspension of phospholipid liposomes) in comparison with free doxorubicin (Doxorubicin-Teva) and protected doxorubicin (Caelyx) was performed on transplanted murine tumor models. All these drugs were efficient in Ca755 breast carcinoma model (tumor growth inhibition ≈100%, increase in lifespan 90.6-114.3%). In P388 lymphocytic leukemia and LLC lung carcinoma, advantages of the protected doxorubicin by the benefit/risk ratio (width of therapeutic interval) were demonstrated: Caelyx>Doxorubicin-NPh>Doxorubicin-Teva. Doxorubicin-NPh and Caelyx exhibited similar therapeutic activity in the LLC model, especially when administered 3 times with 3-day intervals; for Doxorubicin-Teva, the optimal interval between the injections was 7 days.

[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.

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.

[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.

[The increase in receptor-mediated endocytosis of drugs in the composition of nanoparticles with the address fragment]. / Uvelichenie éndotsitoza protivoopukholevykh lekarstv v sostave nanochastits s adresnym fragmentom.

It is known that disorders in the cell functioning of the organs/tissues is accompanied by increased expression of certain receptors. A modern approach to improve the specificity of the drug accumulation in the affected area is to construct the delivery nanosystems with the address fragments. Active tagged transport may help to reduce the dose of the drug, minimizing the impact on healthy cells and organs (reduced adverse events). This approach is particularly important in oncology because of the high toxicity of the drugs used. In this work we have obtained and characterized the pharmaceutical composition of doxorubicin and chlorine e6 into colloidal nanoparticles with synthesized previously targeted conjugates based on folic acid and biotin. On the cell culture Hep G2 it was shown an increase in the internalization of drugs when they were introduced in the incubation medium in the form of drug compositions with transport nanosystems and targeted fragments.

[The in vivo study of the medicinal composition property of doxorubicin as a part of colloidal nanoparticles with the address fragment].

The use of targeted transport systems for drug delivery is a promising approach to improve pharmacokinetics of drug substances, accumulation in the lesion. In this study we have obtained and characterized the pharmaceutical composition of doxorubicin in colloidal nanoparticles equipped with targeted conjugates based on folic acid and biotin with dodecylamine. The inclusion of the address fragments into colloidal nanopartical was carried out without surface and drug substance modification The accumulation of anthracycline antibiotic doxorubicin in tumor tissue was compared in Lewis lung carcinoma mouse models after intravenous administration of the composition of colloidal nanoparticles with targeted conjugates biotin-dodecylamine and folic acid-dodecylamine or free doxorubicin. It was shown that the doxorubicin accumulation in tumor tissue when administered in drug compositions with targeted fragments are 2 times higher for the folic acid-dodecylamine conjugate and 1.4 times higher for the biotin-dodecylamine conjugate.