Natalia Kuznetsova | Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry (original) (raw)
Papers by Natalia Kuznetsova
![Research paper thumbnail of [Liposome formulations of combretastatin A4 and 4-arylcoumarin analog prodrugs: antitumor effect in the mouse model of breast cancer]](https://attachments.academia-assets.com/67182880/thumbnails/1.jpg)
](Biomedit͡sinskai͡a khimii͡a
The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for an... more The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for anticancer therapy relatively recently. To reduce systemic toxicity by means of administration in liposome formulations, in this study new lipophilic prodrugs, oleic derivatives of CA-4 and its 4-arylcoumarin analog (CA4-Ole and ArC-Ole, respectively), have been synthesized: Liposomes of 100 nm mean diameter prepared on the basis of egg phosphatidylcholine and phosphatidylinositol from bakers yeast have been shown to include completely up to 10 mol. % of CA4-Ole, or 7 mol. % of ArC-Ole. Also, prodrug bearing liposomes decorated with tetrasaccharide selectin ligand Sialyl Lewis X (SiaLe(x)) have been constructed to achieve targeting to endothelium under neovascularization. The antitumor activity in vivo was studied in the model of slowly growing mouse breast cancer. Under the used dose (22 mg/kg) as well as the regimen of treatment (four injections, one per a week, starting from the appeara...
Nanotechnologies in Russia, 2008
The inclusion of antitumor agents into nanodimensional carriers such as 100-to 150-nm liposomes m... more The inclusion of antitumor agents into nanodimensional carriers such as 100-to 150-nm liposomes makes it possible to reduce the general toxicity of chemotherapeutic drugs by decreasing the free drug concentration in the blood flow and by increasing the passive transport and accumulation of nanocarriers in tumors due to enhanced permeability of defective capillary vessel walls. On the other hand, biodegradable lipid-drug conjugates (lipophilic prodrugs) possess improved pharmacokinetics. In this study, we have determined detailed characteristics of the liposomal formulations of the antitumor drugs melphalan and methotrexate conjugated to rac -1,2-dioleoylglycerol, which contain the drugs in amounts (~4 mM) sufficient for systemic injections into experimental animals. The liposomes were prepared from a mixture of natural phospholipids and prodrugs (phosphatidylcholine-phosphatidylinositol-prodrug molar ratio, 8 : 1 : 1) by the standard method of extrusion through polycarbonate membranes with 100-nm pores. The liposome size, lamellarity, and degree of aggregation were determined by methods of dynamic (laser) light scattering and transmission electron microscopy (using negative contrasting and freeze fracture techniques), while the liposome composition was checked using gel chromatography with subsequent UV spectrophotometry. It has been established that both diglyceride lipiddrug conjugates are completely included into unilamellar liposomes (bounded by a single lipid bilayer) with an average size of 50-150 nm and this dispersion can be stored for several days without any signs of significant aggregation. The possibility of obtaining liposomal preparations for long-term storage has been studied. It is demonstrated that liposomal drug dispersions can be subjected to deep freezing in liquid nitrogen and then stored for a long period of time at -70 ° C. For subsequent usage, the dispersion should be defrozen and treated for a short time in an ultrasonic bath, which completely restores the composition and size of the initial particles. Experiments in vitro have shown that a liposomal methotrexate conjugate is capable of overcoming tumor cell resistance to the drug, which is related to impaired transmembrane transport. The drug resistance of human leukemia cells related to a decreased activity of a transport protein (reduced folate carrier) has been decreased 114 times for methotrexate conjugate in liposomal formulation compared to the initial drug.
Journal of nanoscience and nanotechnology, 2015
In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel an... more In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel anticancer nanosized formulations, such as docetaxel-loaded nanoemulsion and liposomal formulation of a lipophilic methotrexate (MTX) prodrug. In vitro study of cytotoxicity was carried out in 2 models, namely using 3D in vitro model based on multicellular tumor spheroids (MTS) and 2D monolayer culture. MTS were generated by tumor cell cultivation within alginate-oligochitosan microcapsules. In the case of the monolayer culture, cell viability was found to be 25, 18 and 12% for the samples containing nanoemulsion at concentrations 20, 300 and 1000 nM of docetaxel, respectively, after 48 hs incubation. For MTS these values were higher, namely 33, 23 and 18%, respectively. Cytotoxicity of liposomal MTX prodrug-based formulation with final concentration of 1, 2, 10, 50, 100 and 1000 nM in both models was also studied. MTX liposomal formulation demonstrated lower cytotoxicity on MTS compared t...
Colloids and Surfaces B: Biointerfaces, 2015
Magnetic fluid-loaded liposomes (MFLs) were fabricated using magnetite nanoparticles (MNPs) and n... more Magnetic fluid-loaded liposomes (MFLs) were fabricated using magnetite nanoparticles (MNPs) and natural phospholipids via the thin film hydration method followed by extrusion. The size distribution and composition of MFLs were studied using dynamic light scattering and spectrophotometry. The effective ranges of magnetite concentration in MNPs hydrosol and MFLs for contrasting at both T2 and T1 relaxation were determined. On T2 weighted images, the MFLs effectively increased the contrast if compared with MNPs hydrosol, while on T1 weighted images, MNPs hydrosol contrasting was more efficient than that of MFLs. In vivo magnetic resonance imaging (MRI) contrasting properties of MFLs and their effects on tumor and normal tissues morphology, were investigated in rats with transplanted renal cell carcinoma upon intratumoral administration of MFLs. No significant morphological changes in rat internal organs upon intratumoral injection of MFLs were detected, suggesting that the liposomes are relatively safe and can be used as the potential contrasting agents for MRI.
Bioorganicheskaia khimiia
Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for... more Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for anticancer therapy. To reduce their systemic toxicity and improve biodistribution, encapsulation in nanosized liposomes may be employed. Liposomes present a convenient means for preparation of injectable formulations of hydrophobic compounds, however colchicine as such is known to leak through the lipid bilayer. In this study, newly synthesized triazole-containing analogues of colchicine and allocolchicine, and their palmitic and oleic esters (lipophilic prodrugs) were tested for anti-proliferative activity and apoptosis-inducing potential. In contrast to colchicine conjugates, whose activities ranged with those of colchicine, allocolchicine derivatives exhibited drastically lower effects and were discarded. Liposomes of about 100 nm in diameter composed of egg phosphatidylcholine--yeast phosphatidylinositol--palmitic or oleic prodrug, 8 : 1: 1, by mol, were prepared by standard extrusi...
Bioorganicheskaia khimiia
The efficiency of the chemotherapeutic agent methotrexate (MTX) in tumor cells is limited by the ... more The efficiency of the chemotherapeutic agent methotrexate (MTX) in tumor cells is limited by the frequent development of the drug resistance of tumor cells. We had previously shown in vitro using human acute leukemia cells with various sensitivity to MTX (T-lymphoblastic CCRF-CEM line and resistant CEM/MTX subline) that MTX incorporation into liposomes as a lipophilic prodrug, diglyceride conjugate (MTX-DG), allows for the overcoming of cell resistance due to the impaired active transmembrane transport. In this work, we have studied the profile of binding with carbohydrates of the cell lines mentioned using carbohydrate fluorescent probes (poly(acryl amide) conjugates). Lipophilic conjugates of tetrasaccharide SiaLe(x), 6'-HSO3LacNAc, and also inactive pentaol for incorporation into liposomes, have been synthesized. The cytotoxicity of MTX-DG liposomes equipped with the SiaLe(x) ligand toward the sensitive CCRF-CEM cell culture was demonstrated to be 3.5 times higher than that o...
Bioorganicheskaia khimiia
We have recently synthesized a lipid conjugate of the anticancer agent methotrexate (MTX-DG) and ... more We have recently synthesized a lipid conjugate of the anticancer agent methotrexate (MTX-DG) and showed that the conjugate is quantitatively included in the lipid bilayer of liposomes prepared by a standard extrusion technique from an 8 : 1 : 1 (mol) egg phosphatidylcholine-yeast phosphatidylinositol-MTX-DG mixture. Both the size of liposomes (126 +/- 30 nm) and the MTX-DG concentration (4.4 mM) are relevant for systemic injections in mammals. The liposomal formulation of MTX-DG was shown to overcome the resistance of tumor cells in vitro to methotrexate: the cytotoxic activities (IC50) of MTX in cultures of the human T-lymphoblastic leukemia cell line CEM-CCRF and the MTX-resistant subline CEM/MTX were 0.075 +/- 0.005 and 16.4 +/- 4.9 microM, respectively, while, in the case of liposomes loaded with MTX-DG, the IC50 values were much closer: 0.77 +/- 0.06 and 3.8 +/- 1.9 microM.
Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology, 2013
ABSTRACT When used as nanosized carriers, liposomes enable targeted delivery and decrease systemi... more ABSTRACT When used as nanosized carriers, liposomes enable targeted delivery and decrease systemic toxicity of antitumor agents significantly. However, slow unloading of liposomes inside cells diminishes the treatment efficiency. The problem could be overcome by the adoption of lipophilic prodrugs tailored for incorporation into lipid bilayer of liposomes. We prepared liposomes of egg yolk phosphatidylcholine and yeast phosphatidylinositol bearing a diglyceride conjugate of an antitumor antibiotic doxorubicin (a lipophilic prodrug, DOX-DG) in the membrane to study how these formulations interact with tumor cells. We also prepared liposomes of rigid bilayer-forming lipids, such as a mixture of dipalmitoylphosphatidylcholine and cholesterol, bearing DOX in the inner water volume, both pegylated (with polyethylene glycol (PEG) chains exposed to water phase) and non-pegylated. Efficiency of binding of free and liposomal doxorubicin with tumor cells was evaluated in vitro using spectrofluorimetry of cell extracts and flow cytometry. Intracellular traffic of the formulations was investigated by confocal microscopy; co-localization of DOX fluorescence with organelle trackers was estimated. All liposomal formulations of DOX were shown to distribute to organelles retarding its transport to nucleus. Intracellular distribution of liposomal DOX depended on liposome structure and pegylation. We conclude that the most probable mechanism of the lipophilic prodrug penetration into a cell is liposome-mediated endosomal pathway.
Journal of Nanoscience and Nanotechnology, 2015
In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel an... more In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel anticancer nanosized formulations, such as docetaxel-loaded nanoemulsion and liposomal formulation of a lipophilic methotrexate (MTX) prodrug. In vitro study of cytotoxicity was carried out in 2 models, namely using 3D in vitro model based on multicellular tumor spheroids (MTS) and 2D monolayer culture. MTS were generated by tumor cell cultivation within alginate-oligochitosan microcapsules. In the case of the monolayer culture, cell viability was found to be 25, 18 and 12% for the samples containing nanoemulsion at concentrations 20, 300 and 1000 nM of docetaxel, respectively, after 48 hs incubation. For MTS these values were higher, namely 33, 23 and 18%, respectively. Cytotoxicity of liposomal MTX prodrug-based formulation with final concentration of 1, 2, 10, 50, 100 and 1000 nM in both models was also studied. MTX liposomal formulation demonstrated lower cytotoxicity on MTS compared to intact MTX. Moreover, MTS were also more resistant to both liposomal formulation and intact MTX than the monolayer culture. Thus, at 1000 nM MTX in the liposomal form, cell viability in MTS was 1.4-fold higher than that in the monolayer culture. MTS could be proposed as a promising tool to test novel anticancer nanosized formulations in vitro.
Journal of Drug Targeting, 2014
Abstract Earlier we showed that liposome formulation of DL-melphalan lipophilic prodrug bearing t... more Abstract Earlier we showed that liposome formulation of DL-melphalan lipophilic prodrug bearing tetrasaccharide Sialyl Lewis X (SiaLe(X)) caused prolonged therapeutic effect on mammary cancer in mice. Here, we compare antivascular effect of SiaLe(X)-liposomes loaded with diglyceride ester of melphalan (Mlph) against SiaLe(X)-free formulation in Lewis lung carcinoma model. Methods: Liposomes of egg phosphatidylcholine/yeast phosphatidylinositol/1,2-dioleoyl glycerol (DOG) conjugate of Mlph/±SiaLe(X)-PEG8-15-DOG, 8:1:1:0.2 by mol, were prepared by standard extrusion. After two intravenous injections with Mlph or liposomes under either standard or delayed treatment protocols, vascular-disrupting effects of the preparations were evaluated basing on tumour section histomorphology, lectin perfusion assay and immunohistochemistry (anti-CD31 staining) data. Also, untreated mice were administered with fluorescently-labelled liposomes to assess their distribution in tumour sections with confocal laser scanning microscopy. Results: Two injections of SiaLe(X)-liposomes reproducibly caused severe injuries of tumour vessels. SiaLe(X)-liposomes co-localized with CD31 marker on vascular endothelium while the non-targeted formulation extravasated into tumour. Discussion: Cytotoxic SiaLe(X)-liposomes exhibit superior vascular-disrupting properties compared to non-targeted liposomes, yet the effect starts to transform into gain in tumour growth inhibition only under delayed treatment regimen. Conclusion: SiaLe(X)-ligand provides targeting of cytotoxic liposomes to tumour endothelium and subsequent antivascular effect.
Crystallography Reports, 2008
ABSTRACT The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na2[Co(NO3)4] ... more ABSTRACT The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na2[Co(NO3)4] (I) and K2[Co(NO3)4] (II)] and a chain structure [Ag[Co(NO3)3] (III) and K2[Ni(NO3)4] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO3)4]2− of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO3)4]2− of the crystal structure of compound II, one of the four NO3 groups is monodentate and the other NO3 groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO3)2(NO3)2/2]− and [Ni(NO3)3(NO3)2/2]2−, respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.
![Research paper thumbnail of [Liposome formulations of combretastatin A4 and 4-arylcoumarin analog prodrugs: antitumor effect in the mouse model of breast cancer]](https://attachments.academia-assets.com/39996819/thumbnails/1.jpg)
](Biomedit͡sinskai͡a khimii͡a
The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for an... more The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for anticancer therapy relatively recently. To reduce systemic toxicity by means of administration in liposome formulations, in this study new lipophilic prodrugs, oleic derivatives of CA-4 and its 4-arylcoumarin analog (CA4-Ole and ArC-Ole, respectively), have been synthesized: Liposomes of 100 nm mean diameter prepared on the basis of egg phosphatidylcholine and phosphatidylinositol from bakers yeast have been shown to include completely up to 10 mol. % of CA4-Ole, or 7 mol. % of ArC-Ole. Also, prodrug bearing liposomes decorated with tetrasaccharide selectin ligand Sialyl Lewis X (SiaLe(x)) have been constructed to achieve targeting to endothelium under neovascularization. The antitumor activity in vivo was studied in the model of slowly growing mouse breast cancer. Under the used dose (22 mg/kg) as well as the regimen of treatment (four injections, one per a week, starting from the appeara...
A panel of in vitro tests intended for evaluation of the nano-sized drug delivery systems' compli... more A panel of in vitro tests intended for evaluation of the nano-sized drug delivery systems' compliance with human blood was applied to liposomal formulations of anticancer lipophilic prodrugs incorporated into the lipid bilayer. Liposomes on the basis of natural phosphatidylcholine (PC) and phosphatidylinositol (PI), 8:1 (mol) were loaded with 10 mol% of either methotrexate or melphalan 1,2-dioleoylglyceride esters (MTX-DOG and Mlph-DOG respectively) and either decorated with 2 mol% of sialyl Lewis X/A (SiaLe X/A ) tetrasaccharide ligand or not. Hemolysis rate, red blood cells and platelets integrity and size distribution, complement (C) activation, and coagulation cascade functioning were analyzed upon the material incubation with whole blood. Both formulations were negatively charged with the zeta potential value being higher in the case of MTX-DOG liposomes, which also were larger than Mlph-DOG liposomes and more prone to aggregation. Accordingly, in hemocompatibility tests Mlph-DOG liposomes did not provoke any undesirable effects, while MTX-DOG liposomes induced significant C activation and abnormal coagulation times in a concentration-dependent manner. Reactivity of the liposome surface was not affected by the presence of SiaLe X/A or PI. Decrease in liposome loading with MTX-DOG from 10 to 2.5% resulted in lower surface charge density, smaller liposome size and considerably reduced impact on C activation and coagulation cascades.
Biomedit͡sinskai͡a khimii͡a
The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for an... more The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for anticancer therapy relatively recently. To reduce systemic toxicity by means of administration in liposome formulations, in this study new lipophilic prodrugs, oleic derivatives of CA-4 and its 4-arylcoumarin analog (CA4-Ole and ArC-Ole, respectively), have been synthesized: Liposomes of 100 nm mean diameter prepared on the basis of egg phosphatidylcholine and phosphatidylinositol from bakers yeast have been shown to include completely up to 10 mol. % of CA4-Ole, or 7 mol. % of ArC-Ole. Also, prodrug bearing liposomes decorated with tetrasaccharide selectin ligand Sialyl Lewis X (SiaLe(x)) have been constructed to achieve targeting to endothelium under neovascularization. The antitumor activity in vivo was studied in the model of slowly growing mouse breast cancer. Under the used dose (22 mg/kg) as well as the regimen of treatment (four injections, one per a week, starting from the appeara...
Nanotechnologies in Russia, 2008
The inclusion of antitumor agents into nanodimensional carriers such as 100-to 150-nm liposomes m... more The inclusion of antitumor agents into nanodimensional carriers such as 100-to 150-nm liposomes makes it possible to reduce the general toxicity of chemotherapeutic drugs by decreasing the free drug concentration in the blood flow and by increasing the passive transport and accumulation of nanocarriers in tumors due to enhanced permeability of defective capillary vessel walls. On the other hand, biodegradable lipid-drug conjugates (lipophilic prodrugs) possess improved pharmacokinetics. In this study, we have determined detailed characteristics of the liposomal formulations of the antitumor drugs melphalan and methotrexate conjugated to rac -1,2-dioleoylglycerol, which contain the drugs in amounts (~4 mM) sufficient for systemic injections into experimental animals. The liposomes were prepared from a mixture of natural phospholipids and prodrugs (phosphatidylcholine-phosphatidylinositol-prodrug molar ratio, 8 : 1 : 1) by the standard method of extrusion through polycarbonate membranes with 100-nm pores. The liposome size, lamellarity, and degree of aggregation were determined by methods of dynamic (laser) light scattering and transmission electron microscopy (using negative contrasting and freeze fracture techniques), while the liposome composition was checked using gel chromatography with subsequent UV spectrophotometry. It has been established that both diglyceride lipiddrug conjugates are completely included into unilamellar liposomes (bounded by a single lipid bilayer) with an average size of 50-150 nm and this dispersion can be stored for several days without any signs of significant aggregation. The possibility of obtaining liposomal preparations for long-term storage has been studied. It is demonstrated that liposomal drug dispersions can be subjected to deep freezing in liquid nitrogen and then stored for a long period of time at -70 ° C. For subsequent usage, the dispersion should be defrozen and treated for a short time in an ultrasonic bath, which completely restores the composition and size of the initial particles. Experiments in vitro have shown that a liposomal methotrexate conjugate is capable of overcoming tumor cell resistance to the drug, which is related to impaired transmembrane transport. The drug resistance of human leukemia cells related to a decreased activity of a transport protein (reduced folate carrier) has been decreased 114 times for methotrexate conjugate in liposomal formulation compared to the initial drug.
Journal of nanoscience and nanotechnology, 2015
In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel an... more In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel anticancer nanosized formulations, such as docetaxel-loaded nanoemulsion and liposomal formulation of a lipophilic methotrexate (MTX) prodrug. In vitro study of cytotoxicity was carried out in 2 models, namely using 3D in vitro model based on multicellular tumor spheroids (MTS) and 2D monolayer culture. MTS were generated by tumor cell cultivation within alginate-oligochitosan microcapsules. In the case of the monolayer culture, cell viability was found to be 25, 18 and 12% for the samples containing nanoemulsion at concentrations 20, 300 and 1000 nM of docetaxel, respectively, after 48 hs incubation. For MTS these values were higher, namely 33, 23 and 18%, respectively. Cytotoxicity of liposomal MTX prodrug-based formulation with final concentration of 1, 2, 10, 50, 100 and 1000 nM in both models was also studied. MTX liposomal formulation demonstrated lower cytotoxicity on MTS compared t...
Colloids and Surfaces B: Biointerfaces, 2015
Magnetic fluid-loaded liposomes (MFLs) were fabricated using magnetite nanoparticles (MNPs) and n... more Magnetic fluid-loaded liposomes (MFLs) were fabricated using magnetite nanoparticles (MNPs) and natural phospholipids via the thin film hydration method followed by extrusion. The size distribution and composition of MFLs were studied using dynamic light scattering and spectrophotometry. The effective ranges of magnetite concentration in MNPs hydrosol and MFLs for contrasting at both T2 and T1 relaxation were determined. On T2 weighted images, the MFLs effectively increased the contrast if compared with MNPs hydrosol, while on T1 weighted images, MNPs hydrosol contrasting was more efficient than that of MFLs. In vivo magnetic resonance imaging (MRI) contrasting properties of MFLs and their effects on tumor and normal tissues morphology, were investigated in rats with transplanted renal cell carcinoma upon intratumoral administration of MFLs. No significant morphological changes in rat internal organs upon intratumoral injection of MFLs were detected, suggesting that the liposomes are relatively safe and can be used as the potential contrasting agents for MRI.
Bioorganicheskaia khimiia
Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for... more Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for anticancer therapy. To reduce their systemic toxicity and improve biodistribution, encapsulation in nanosized liposomes may be employed. Liposomes present a convenient means for preparation of injectable formulations of hydrophobic compounds, however colchicine as such is known to leak through the lipid bilayer. In this study, newly synthesized triazole-containing analogues of colchicine and allocolchicine, and their palmitic and oleic esters (lipophilic prodrugs) were tested for anti-proliferative activity and apoptosis-inducing potential. In contrast to colchicine conjugates, whose activities ranged with those of colchicine, allocolchicine derivatives exhibited drastically lower effects and were discarded. Liposomes of about 100 nm in diameter composed of egg phosphatidylcholine--yeast phosphatidylinositol--palmitic or oleic prodrug, 8 : 1: 1, by mol, were prepared by standard extrusi...
Bioorganicheskaia khimiia
The efficiency of the chemotherapeutic agent methotrexate (MTX) in tumor cells is limited by the ... more The efficiency of the chemotherapeutic agent methotrexate (MTX) in tumor cells is limited by the frequent development of the drug resistance of tumor cells. We had previously shown in vitro using human acute leukemia cells with various sensitivity to MTX (T-lymphoblastic CCRF-CEM line and resistant CEM/MTX subline) that MTX incorporation into liposomes as a lipophilic prodrug, diglyceride conjugate (MTX-DG), allows for the overcoming of cell resistance due to the impaired active transmembrane transport. In this work, we have studied the profile of binding with carbohydrates of the cell lines mentioned using carbohydrate fluorescent probes (poly(acryl amide) conjugates). Lipophilic conjugates of tetrasaccharide SiaLe(x), 6'-HSO3LacNAc, and also inactive pentaol for incorporation into liposomes, have been synthesized. The cytotoxicity of MTX-DG liposomes equipped with the SiaLe(x) ligand toward the sensitive CCRF-CEM cell culture was demonstrated to be 3.5 times higher than that o...
Bioorganicheskaia khimiia
We have recently synthesized a lipid conjugate of the anticancer agent methotrexate (MTX-DG) and ... more We have recently synthesized a lipid conjugate of the anticancer agent methotrexate (MTX-DG) and showed that the conjugate is quantitatively included in the lipid bilayer of liposomes prepared by a standard extrusion technique from an 8 : 1 : 1 (mol) egg phosphatidylcholine-yeast phosphatidylinositol-MTX-DG mixture. Both the size of liposomes (126 +/- 30 nm) and the MTX-DG concentration (4.4 mM) are relevant for systemic injections in mammals. The liposomal formulation of MTX-DG was shown to overcome the resistance of tumor cells in vitro to methotrexate: the cytotoxic activities (IC50) of MTX in cultures of the human T-lymphoblastic leukemia cell line CEM-CCRF and the MTX-resistant subline CEM/MTX were 0.075 +/- 0.005 and 16.4 +/- 4.9 microM, respectively, while, in the case of liposomes loaded with MTX-DG, the IC50 values were much closer: 0.77 +/- 0.06 and 3.8 +/- 1.9 microM.
Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology, 2013
ABSTRACT When used as nanosized carriers, liposomes enable targeted delivery and decrease systemi... more ABSTRACT When used as nanosized carriers, liposomes enable targeted delivery and decrease systemic toxicity of antitumor agents significantly. However, slow unloading of liposomes inside cells diminishes the treatment efficiency. The problem could be overcome by the adoption of lipophilic prodrugs tailored for incorporation into lipid bilayer of liposomes. We prepared liposomes of egg yolk phosphatidylcholine and yeast phosphatidylinositol bearing a diglyceride conjugate of an antitumor antibiotic doxorubicin (a lipophilic prodrug, DOX-DG) in the membrane to study how these formulations interact with tumor cells. We also prepared liposomes of rigid bilayer-forming lipids, such as a mixture of dipalmitoylphosphatidylcholine and cholesterol, bearing DOX in the inner water volume, both pegylated (with polyethylene glycol (PEG) chains exposed to water phase) and non-pegylated. Efficiency of binding of free and liposomal doxorubicin with tumor cells was evaluated in vitro using spectrofluorimetry of cell extracts and flow cytometry. Intracellular traffic of the formulations was investigated by confocal microscopy; co-localization of DOX fluorescence with organelle trackers was estimated. All liposomal formulations of DOX were shown to distribute to organelles retarding its transport to nucleus. Intracellular distribution of liposomal DOX depended on liposome structure and pegylation. We conclude that the most probable mechanism of the lipophilic prodrug penetration into a cell is liposome-mediated endosomal pathway.
Journal of Nanoscience and Nanotechnology, 2015
In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel an... more In the study, MCF-7 human breast adenocarcinoma cells were used to study cytotoxicity of novel anticancer nanosized formulations, such as docetaxel-loaded nanoemulsion and liposomal formulation of a lipophilic methotrexate (MTX) prodrug. In vitro study of cytotoxicity was carried out in 2 models, namely using 3D in vitro model based on multicellular tumor spheroids (MTS) and 2D monolayer culture. MTS were generated by tumor cell cultivation within alginate-oligochitosan microcapsules. In the case of the monolayer culture, cell viability was found to be 25, 18 and 12% for the samples containing nanoemulsion at concentrations 20, 300 and 1000 nM of docetaxel, respectively, after 48 hs incubation. For MTS these values were higher, namely 33, 23 and 18%, respectively. Cytotoxicity of liposomal MTX prodrug-based formulation with final concentration of 1, 2, 10, 50, 100 and 1000 nM in both models was also studied. MTX liposomal formulation demonstrated lower cytotoxicity on MTS compared to intact MTX. Moreover, MTS were also more resistant to both liposomal formulation and intact MTX than the monolayer culture. Thus, at 1000 nM MTX in the liposomal form, cell viability in MTS was 1.4-fold higher than that in the monolayer culture. MTS could be proposed as a promising tool to test novel anticancer nanosized formulations in vitro.
Journal of Drug Targeting, 2014
Abstract Earlier we showed that liposome formulation of DL-melphalan lipophilic prodrug bearing t... more Abstract Earlier we showed that liposome formulation of DL-melphalan lipophilic prodrug bearing tetrasaccharide Sialyl Lewis X (SiaLe(X)) caused prolonged therapeutic effect on mammary cancer in mice. Here, we compare antivascular effect of SiaLe(X)-liposomes loaded with diglyceride ester of melphalan (Mlph) against SiaLe(X)-free formulation in Lewis lung carcinoma model. Methods: Liposomes of egg phosphatidylcholine/yeast phosphatidylinositol/1,2-dioleoyl glycerol (DOG) conjugate of Mlph/±SiaLe(X)-PEG8-15-DOG, 8:1:1:0.2 by mol, were prepared by standard extrusion. After two intravenous injections with Mlph or liposomes under either standard or delayed treatment protocols, vascular-disrupting effects of the preparations were evaluated basing on tumour section histomorphology, lectin perfusion assay and immunohistochemistry (anti-CD31 staining) data. Also, untreated mice were administered with fluorescently-labelled liposomes to assess their distribution in tumour sections with confocal laser scanning microscopy. Results: Two injections of SiaLe(X)-liposomes reproducibly caused severe injuries of tumour vessels. SiaLe(X)-liposomes co-localized with CD31 marker on vascular endothelium while the non-targeted formulation extravasated into tumour. Discussion: Cytotoxic SiaLe(X)-liposomes exhibit superior vascular-disrupting properties compared to non-targeted liposomes, yet the effect starts to transform into gain in tumour growth inhibition only under delayed treatment regimen. Conclusion: SiaLe(X)-ligand provides targeting of cytotoxic liposomes to tumour endothelium and subsequent antivascular effect.
Crystallography Reports, 2008
ABSTRACT The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na2[Co(NO3)4] ... more ABSTRACT The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na2[Co(NO3)4] (I) and K2[Co(NO3)4] (II)] and a chain structure [Ag[Co(NO3)3] (III) and K2[Ni(NO3)4] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO3)4]2− of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO3)4]2− of the crystal structure of compound II, one of the four NO3 groups is monodentate and the other NO3 groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO3)2(NO3)2/2]− and [Ni(NO3)3(NO3)2/2]2−, respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.
Biomedit͡sinskai͡a khimii͡a
The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for an... more The antimitotic agent combretastatin A4 (CA-4) has been suggested as an antivascular agent for anticancer therapy relatively recently. To reduce systemic toxicity by means of administration in liposome formulations, in this study new lipophilic prodrugs, oleic derivatives of CA-4 and its 4-arylcoumarin analog (CA4-Ole and ArC-Ole, respectively), have been synthesized: Liposomes of 100 nm mean diameter prepared on the basis of egg phosphatidylcholine and phosphatidylinositol from bakers yeast have been shown to include completely up to 10 mol. % of CA4-Ole, or 7 mol. % of ArC-Ole. Also, prodrug bearing liposomes decorated with tetrasaccharide selectin ligand Sialyl Lewis X (SiaLe(x)) have been constructed to achieve targeting to endothelium under neovascularization. The antitumor activity in vivo was studied in the model of slowly growing mouse breast cancer. Under the used dose (22 mg/kg) as well as the regimen of treatment (four injections, one per a week, starting from the appeara...
A panel of in vitro tests intended for evaluation of the nano-sized drug delivery systems' compli... more A panel of in vitro tests intended for evaluation of the nano-sized drug delivery systems' compliance with human blood was applied to liposomal formulations of anticancer lipophilic prodrugs incorporated into the lipid bilayer. Liposomes on the basis of natural phosphatidylcholine (PC) and phosphatidylinositol (PI), 8:1 (mol) were loaded with 10 mol% of either methotrexate or melphalan 1,2-dioleoylglyceride esters (MTX-DOG and Mlph-DOG respectively) and either decorated with 2 mol% of sialyl Lewis X/A (SiaLe X/A ) tetrasaccharide ligand or not. Hemolysis rate, red blood cells and platelets integrity and size distribution, complement (C) activation, and coagulation cascade functioning were analyzed upon the material incubation with whole blood. Both formulations were negatively charged with the zeta potential value being higher in the case of MTX-DOG liposomes, which also were larger than Mlph-DOG liposomes and more prone to aggregation. Accordingly, in hemocompatibility tests Mlph-DOG liposomes did not provoke any undesirable effects, while MTX-DOG liposomes induced significant C activation and abnormal coagulation times in a concentration-dependent manner. Reactivity of the liposome surface was not affected by the presence of SiaLe X/A or PI. Decrease in liposome loading with MTX-DOG from 10 to 2.5% resulted in lower surface charge density, smaller liposome size and considerably reduced impact on C activation and coagulation cascades.