Pavel Melnikov - Academia.edu (original) (raw)

Papers by Pavel Melnikov

Life

Systemic transplantation of mesenchymal stem cells (MSCs) is a promising approach for the treatme... more Systemic transplantation of mesenchymal stem cells (MSCs) is a promising approach for the treatment of ischemia-associated disorders, including stroke. However, exact mechanisms underlying its beneficial effects are still debated. In this respect, studies of the transplanted cells distribution and homing are indispensable. We proposed an MRI protocol which allowed us to estimate the dynamic distribution of single superparamagnetic iron oxide labeled MSCs in live ischemic rat brain during intravenous transplantation after the transient middle cerebral artery occlusion. Additionally, we evaluated therapeutic efficacy of cell therapy in this rat stroke model. According to the dynamic MRI data, limited numbers of MSCs accumulated diffusely in the brain vessels starting at the 7th minute from the onset of infusion, reached its maximum by 29 min, and gradually eliminated from cerebral circulation during 24 h. Despite low numbers of cells entering brain blood flow and their short-term engr...

International Journal of Molecular Sciences

The development of new neurotherapeutics depends on appropriate animal models being chosen in pre... more The development of new neurotherapeutics depends on appropriate animal models being chosen in preclinical studies. The cuprizone model is an effective tool for studying demyelination and remyelination processes in the brain, but blood–brain barrier (BBB) integrity in the cuprizone model is still a topic for debate. Several publications claim that the BBB remains intact during cuprizone-induced demyelination; others demonstrate results that could explain the increased BBB permeability. In this study, we aim to analyze the permeability of the BBB for different macromolecules, particularly antibody conjugates, in a cuprizone-induced model of demyelination. We compared the traditional approach using Evans blue injection with subsequent dye extraction and detection of antibody conjugates using magnetic resonance imaging (MRI) and confocal microscopy to analyze BBB permeability in the cuprizone model. First, we validated our model of demyelination by performing T2-weighted MRI, diffusion ...

International Journal of Molecular Sciences

Introducing a new genetically encoded material containing a photoactivatable label as a model car... more Introducing a new genetically encoded material containing a photoactivatable label as a model cargo protein, based on Myxococcus xanthus (Mx) encapsulin system stably expressed in human 293T cells. Encapsulin from Mx is known to be a protein-based container for a ferritin-like cargo in its shell which could be replaced with an exogenous cargo protein, resulting in a modified encapsulin system. We replaced Mx natural cargo with a foreign photoactivatable mCherry (PAmCherry) fluorescent protein and isolated encapsulins, containing PAmCherry, from 293T cells. Isolated Mx encapsulin shells containing photoactivatable label can be internalized by macrophages, wherein the PAmCherry fluorescent signal remains clearly visible. We believe that a genetically encoded nanocarrier system obtained in this study, can be used as a platform for controllable delivery of protein/peptide therapeutics in vitro.

Biomedicines, 2022

Intra-arterial (IA) mesenchymal stem cells (MSCs) transplantation providing targeted cell deliver... more Intra-arterial (IA) mesenchymal stem cells (MSCs) transplantation providing targeted cell delivery to brain tissue is a promising approach to the treatment of neurological disorders, including stroke. Factors determining cell distribution after IA administration have not been fully elucidated. Their decoding may contribute to the improvement of a transplantation technique and facilitate translation of stroke cell therapy into clinical practice. The goal of this work was to quantitatively assess the impact of brain tissue perfusion on the distribution of IA transplanted MSCs in rat brains. We performed a selective MR-perfusion study with bolus IA injection of gadolinium-based contrast agent and subsequent IA transplantation of MSCs in intact rats and rats with experimental stroke and evaluated the correlation between different perfusion parameters and cell distribution estimated by susceptibility weighted imaging (SWI) immediately after cell transplantation. The obtained results reve...

Nucleic Acid Therapeutics, 2021

A series of 2'-deoxy and novel 2'-O-methyl and 2'-O-(2-methoxyethyl) (2'-MOE) oligonucleotides wi... more A series of 2'-deoxy and novel 2'-O-methyl and 2'-O-(2-methoxyethyl) (2'-MOE) oligonucleotides with internucleotide methanesulfonyl (mesyl, μ) or 1butanesulfonyl (busyl, β) phosphoramidate groups have been synthesized for evaluation as potential splice-switching oligonucleotides. Evaluation of their spliceswitching activity in spinal muscular atrophy (SMA) patient derived fibroblasts revealed no significant difference in splice-switching efficacy between 2'-MOE mesyl oligonucleotide and the corresponding phosphorothioate (nusinersen). Yet, a survival study with model neonatal mice have shown the antisense 2'-MOE mesyl oligonucleotide to be inferior to nusinersen at the highest dose of 40 mg/kg. A reason for their lower activity in vivo as ascertained by cellular uptake study via fluorescent confocal microscopy in HEK293 cell line could possibly be ascribed to compromised endosomal release and/or nuclear uptake of the 2'-OMe or 2'-MOE μand β-oligonucleotides as compared to their phosphorothioate analog.

Frontiers in Neuroscience, 2021

Cell therapy is an emerging approach to stroke treatment with a potential to limit brain damage a... more Cell therapy is an emerging approach to stroke treatment with a potential to limit brain damage and enhance its restoration after the acute phase of the disease. In this study we tested directly reprogrammed neural precursor cells (drNPC) derived from adult human bone marrow cells in the rat middle cerebral artery occlusion (MCAO) model of acute ischemic stroke using human placenta mesenchymal stem cells (pMSC) as a positive control with previously confirmed efficacy. Cells were infused into the ipsilateral (right) internal carotid artery of male Wistar rats 24 h after MCAO. The main goal of this work was to evaluate real-time distribution and subsequent homing of transplanted cells in the brain. This was achieved by performing intra-arterial infusion directly inside the MRI scanner and allowed transplanted cells tracing starting from their first pass through the brain vessels. Immediately after transplantation, cells were observed in the periphery of the infarct zone and in the bra...

Cellular and Molecular Life Sciences, 2020

Fluorescent proteins are commonly used to label target proteins in live cells. However, the conve... more Fluorescent proteins are commonly used to label target proteins in live cells. However, the conventional approach based on covalent fusion of targeted proteins with fluorescent protein probes is limited by the slow rate of fluorophore maturation and irretrievable loss of fluorescence due to photobleaching. Here we report a genetically encoded protein labeling system utilizing transient interactions of small, 21-28 residues-long helical protein tags (K/E coils, KEC). In this system, a protein of interest, covalently tagged with a single coil, is visualized through binding to a cytoplasmic fluorescent protein carrying a complementary coil. The reversible heterodimerization of KECs, whose affinity can be tuned in a broad concentration range from nanomolar to micromolar, allows continuous exchange and replenishment of the tag bound to a targeted protein with the entire cytosolic pool of soluble fluorescent coils. We found that, under conditions of partial illumination of living cells, the photostability of labeling with KECs exceeds that of covalently fused fluorescent probes by approximately one order of magnitude. Similarly, single molecule localization microscopy with KECs provided higher labeling density and allowed a

ACS Nano, 2019

Liposomes are the most extensively used nanocarriers in cancer therapy. Despite the advantages th... more Liposomes are the most extensively used nanocarriers in cancer therapy. Despite the advantages these vehicles provide over free drug there are still limitations with regards to the efficiency of liposomes delivery to tumors and off-target accumulation. A better understanding of nanodrugs extravasation mechanisms in different tumor types and normal vessels is needed to improve their antitumor activity. We used intravital microscopy to track for fluorescent liposomes behavior in xenograft tumor models (murine breast cancer 4T1 and melanoma B16, human prostate cancer 22Rv1) and normal skin and identified two distinct extravasation patterns. Microleakage, a local perivascular nanoparticle deposition, was found both in malignant and healthy tissues. This type of liposomes leakage does not provide access to tumor cells and is presumably responsible for drug deposition in normal tissues. In contrast, macroleakage penetrated deep into tissues and localized predominantly on the tumor-host interface. Although neutrophils did not uptake liposomes their extravasation appeared to initiate both micro- and macroleakages. Based on neutrophils and liposomes extravasation dynamics we hypothesized that microleakage and macroleakage are subsequent steps of the extravasation process corresponding to liposomes transport through endothelial and subendothelial barriers. Of note, extravasation spots were detected more often in the proximity of neutrophils, and across studied tumor types neutrophils counts correlated with leakage frequencies. Reduced liposomes accumulation in 4T1 tumors upon Ly6G depletion further corroborated neutrophils role in nanoparticles delivery. Elucidating liposomes extravasation routes has a potential to help improve existing strategies and develop effective nanodrugs for cancer therapy.

Russian Journal of Transplantology and Artificial Organs, 2019

Aim. Neural progenitor cells (NPC) are used for the development of cell therapies of neurological... more Aim. Neural progenitor cells (NPC) are used for the development of cell therapies of neurological diseases. Their stereotaxic transplantation in the middle cerebral artery occlusion (MCAO) model imitating ischemic stroke results in symptom aleviation. However, exploration of less invasive transplantation options is essential, because stereotaxic transplantation is a complex procedure and can be applied to humans only by vital indications in a specialized neurological ward. The aim of the present study was to evaluate the efficacy of cell therapy of the experimental ischemic stroke by the intra-arterial transplantation of NPC.Materials and methods. NPC for transplantation (IPSC-NPC) were derived by two-stage differentiation of cells of a stable line of human induced pluripotent stem cells. Stroke modeling in rats was carried out by transitory 90 min endovascular MCAO by a silicon-tipped filament. NPC were transplanted 24 hours after MCAO. Repetitive magnetic resonance tomography of e...

НАНОМЕДИЦИНА, 2018

Травма спинного мозга (ТСМ) - это травматическое повреждение, не являющееся следствием заболевани... more Травма спинного мозга (ТСМ) - это травматическое повреждение, не являющееся следствием заболевания. Мезенхимальные стволовые клетки (МСК) становятся одним из наиболее используемых типов стволовых клеток как в научных исследованиях, так и в клинических испытаниях. С учетом предыдущих работ, в которых использовали от 4 x 105 до 1 x 106 клеток, целью данного исследования было определить количество МСК, оптимальное для трансплантации при хронической ТСМ. Магнитные наночастицы (НЧ) использовали для доказательства точности проведенной трансплантации. С помощью магнитно-резонансной томографии (МРТ), диффузионно-тензорной визуализации (DTI), диффузионно-тензорной трактографии (DTT) и поведенческих тестов мы проверили влияние различного количества МСК на уменьшение пораженной полости и посттравматического свища, подавление формирования глиального рубца, усиление ремоделирования нейронных волокон, содействие регенерации и прорастанию аксонов, улучшение васкуляризации, повышение уровня экспрес...

Scientific reports, Jan 26, 2018

High-quality, 25 nm octahedral-shaped FeO magnetite nanocrystals are epitaxially grown on 9 nm Au... more High-quality, 25 nm octahedral-shaped FeO magnetite nanocrystals are epitaxially grown on 9 nm Au seed nanoparticles using a modified wet-chemical synthesis. These FeO-Au Janus nanoparticles exhibit bulk-like magnetic properties. Due to their high magnetization and octahedral shape, the hybrids show superior in vitro and in vivo T relaxivity for magnetic resonance imaging as compared to other types of FeO-Au hybrids and commercial contrast agents. The nanoparticles provide two functional surfaces for theranostic applications. For the first time, FeO-Au hybrids are conjugated with two fluorescent dyes or the combination of drug and dye allowing the simultaneous tracking of the nanoparticle vehicle and the drug cargo in vitro and in vivo. The delivery to tumors and payload release are demonstrated in real time by intravital microscopy. Replacing the dyes by cell-specific molecules and drugs makes the FeO-Au hybrids a unique all-in-one platform for theranostics.

Molecular Pharmaceutics, 2016

Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which i... more Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which is the most frequent and aggressive types, is one of the important objectives in nanomedicine. Vascular endothelial growth factor (VEGF) and its receptor type II (VEGFR2) are promising targets, because they are overexpressed by not only core cells but also by migrated glioma cells, which are responsible for resistance and rapid progression of brain tumors. The purpose of the present study was to develop the liposomal drug delivery system combining enhanced loading capacity of cisplatin and high binding affinity to glioma cells. This was achieved by using of highly soluble cisplatin analog, cis-diamminedinitratoplatinum(II), and antibodies against the native form of VEGF or VEGFR2 conjugated to liposome surface. The developed drug delivery system revealed sustained drug release profile, high affinity to antigens as well as increased uptake by glioma C6 and U-87 MG cells. Pharmacokinetic study on glioma C6-bearing rats revealed prolonged blood circulation time of the liposomal formulation. The above features enabled the present drug delivery system to overcome both poor pharmacokinetics typical for Page 2 of 44 ACS Paragon Plus Environment Molecular Pharmaceutics 3 platinum formulations and low loading capacity typical for conventional liposomal cisplatin formulations.

Bulletin of experimental biology and medicine, 2014

The aim of this study was to create a nanocontainer conjugated with monoclonal antibodies to conn... more The aim of this study was to create a nanocontainer conjugated with monoclonal antibodies to connexin 43 (Cx43) that is actively expressed at the periphery of C6 glioma and in the astroglia roll zone. Stable vector nanogels with high (up to 35%) cisplatin load were synthesized. The antitumor effects of Cx43-modified cisplatin-loaded nanogels, free cisplatin, and nonspecific drugs were carried out on C6 glioma model. Vector nanogels reduced systemic toxicity of cisplatin, effectively inhibited tumor growth, and significantly prolonged the lifespan of animals with experimental tumors.

Drug Delivery, 2014

Targeted drug delivery for brain tumor treatment is one of the important objectives in nanomedici... more Targeted drug delivery for brain tumor treatment is one of the important objectives in nanomedicine. Human glioblastoma is the most frequent and aggressive type of brain tumors. The preferential expression of membrane protein connexin 43 (Cx43) and brain-specific anion transporter (BSAT1) in the tumor and peritumoral area is a key component for targeted drug delivery. The purpose of this study was to design cisplatin-loaded nanogels conjugated with monoclonal antibodies to Cx43 and BSAT1 for treatment of intracranial gliomas 101/8. MRI volumetric analysis of tumor-bearing rats indicated significantly reduced tumor volume with cisplatin-loaded targeted-nanogel treatment compared to other formulations. The median survival of rats treated with targeted nanogels conjugated with specific mAbs against extracellular loops of Cx43 and BSAT1 were 27 and 26.6 days higher than that in control group, respectively. For the first time we demonstrated the efficiency of mAb-targeted cisplatin-loaded nanogels in the experimental model of glioma 101/8. This approach could facilitate the development of new drug delivery systems for the treatment of gliomas.

International Journal of Molecular Sciences

Predicting the ability of nanoparticles (NP) to access the tumor is key to the success of chemoth... more Predicting the ability of nanoparticles (NP) to access the tumor is key to the success of chemotherapy using nanotherapeutics. In the present study, the ability of the dual NP-based theranostic system to accumulate in the tumor was evaluated in vivo using intravital microscopy (IVM) and MRI. The system consisted of model therapeutic doxorubicin-loaded poly(lactide-co-glycolide) NP (Dox-PLGA NP) and novel hybrid Ce3/4+-doped maghemite NP encapsulated within the HSA matrix (hMNP) as a supermagnetic MRI contrasting agent. Both NP types had similar sizes of ~100 nm and negative surface potentials. The level of the hMNP and PLGA NP co-distribution in the same regions of interest (ROI, ~2500 µm2) was assessed by IVM in mice bearing the 4T1-mScarlet murine mammary carcinoma at different intervals between the NP injections. In all cases, both NP types penetrated into the same tumoral/peritumoral regions by neutrophil-assisted extravasation through vascular micro- and macroleakages. The maxi...

Biomedicines

Glucose and lipid metabolism are crucial functional systems in eukaryotes. A large number of expe... more Glucose and lipid metabolism are crucial functional systems in eukaryotes. A large number of experimental studies both in animal models and humans have shown that long non-coding RNAs (lncRNAs) play an important role in glucose and lipid metabolism. Previously, human lncRNA DEANR1/linc00261 was described as a tumor suppressor that regulates a variety of biological processes such as cell proliferation, apoptosis, glucose metabolism and tumorigenesis. Here we report that murine lncRNA Falcor/LL35, a proposed functional analog of human DEANR1/linc00261, is predominantly expressed in murine normal hepatocytes and downregulated in HCC and after partial hepatectomy. The application of high-throughput approaches such as RNA-seq, LC-MS proteomics, lipidomics and metabolomics analysis allowed changes to be found in the transcriptome, proteome, lipidome and metabolome of hepatocytes after LL35 depletion. We revealed that LL35 is involved in the regulation of glycolysis and lipid biosynthesis ...

Pharmaceutics, 2021

Fluorescently labeled nanoparticles are widely used for evaluating their distribution in the biol... more Fluorescently labeled nanoparticles are widely used for evaluating their distribution in the biological environment. However, dye leakage can lead to misinterpretations of the nanoparticles’ biodistribution. To better understand the interactions of dyes and nanoparticles and their biological environment, we explored PLGA nanoparticles labeled with four widely used dyes encapsulated (coumarin 6, rhodamine 123, DiI) or bound covalently to the polymer (Cy5.5.). The DiI label was stable in both aqueous and lipophilic environments, whereas the quick release of coumarin 6 was observed in model media containing albumin (42%) or liposomes (62%), which could be explained by the different affinity of these dyes to the polymer and lipophilic structures and which we also confirmed by computational modeling (log PDPPC/PLGA: DiI—2.3, Cou6—0.7). The importance of these factors was demonstrated by in vivo neuroimaging (ICON) of the rat retina using double-labeled Cy5.5/Cou6-nanoparticles: encapsula...

NEUROSCIENCE FOR MEDICINE AND PSYCHOLOGY, 2021

NEUROSCIENCE FOR MEDICINE AND PSYCHOLOGY, 2021

Life

Systemic transplantation of mesenchymal stem cells (MSCs) is a promising approach for the treatme... more Systemic transplantation of mesenchymal stem cells (MSCs) is a promising approach for the treatment of ischemia-associated disorders, including stroke. However, exact mechanisms underlying its beneficial effects are still debated. In this respect, studies of the transplanted cells distribution and homing are indispensable. We proposed an MRI protocol which allowed us to estimate the dynamic distribution of single superparamagnetic iron oxide labeled MSCs in live ischemic rat brain during intravenous transplantation after the transient middle cerebral artery occlusion. Additionally, we evaluated therapeutic efficacy of cell therapy in this rat stroke model. According to the dynamic MRI data, limited numbers of MSCs accumulated diffusely in the brain vessels starting at the 7th minute from the onset of infusion, reached its maximum by 29 min, and gradually eliminated from cerebral circulation during 24 h. Despite low numbers of cells entering brain blood flow and their short-term engr...

International Journal of Molecular Sciences

The development of new neurotherapeutics depends on appropriate animal models being chosen in pre... more The development of new neurotherapeutics depends on appropriate animal models being chosen in preclinical studies. The cuprizone model is an effective tool for studying demyelination and remyelination processes in the brain, but blood–brain barrier (BBB) integrity in the cuprizone model is still a topic for debate. Several publications claim that the BBB remains intact during cuprizone-induced demyelination; others demonstrate results that could explain the increased BBB permeability. In this study, we aim to analyze the permeability of the BBB for different macromolecules, particularly antibody conjugates, in a cuprizone-induced model of demyelination. We compared the traditional approach using Evans blue injection with subsequent dye extraction and detection of antibody conjugates using magnetic resonance imaging (MRI) and confocal microscopy to analyze BBB permeability in the cuprizone model. First, we validated our model of demyelination by performing T2-weighted MRI, diffusion ...

International Journal of Molecular Sciences

Introducing a new genetically encoded material containing a photoactivatable label as a model car... more Introducing a new genetically encoded material containing a photoactivatable label as a model cargo protein, based on Myxococcus xanthus (Mx) encapsulin system stably expressed in human 293T cells. Encapsulin from Mx is known to be a protein-based container for a ferritin-like cargo in its shell which could be replaced with an exogenous cargo protein, resulting in a modified encapsulin system. We replaced Mx natural cargo with a foreign photoactivatable mCherry (PAmCherry) fluorescent protein and isolated encapsulins, containing PAmCherry, from 293T cells. Isolated Mx encapsulin shells containing photoactivatable label can be internalized by macrophages, wherein the PAmCherry fluorescent signal remains clearly visible. We believe that a genetically encoded nanocarrier system obtained in this study, can be used as a platform for controllable delivery of protein/peptide therapeutics in vitro.

Biomedicines, 2022

Intra-arterial (IA) mesenchymal stem cells (MSCs) transplantation providing targeted cell deliver... more Intra-arterial (IA) mesenchymal stem cells (MSCs) transplantation providing targeted cell delivery to brain tissue is a promising approach to the treatment of neurological disorders, including stroke. Factors determining cell distribution after IA administration have not been fully elucidated. Their decoding may contribute to the improvement of a transplantation technique and facilitate translation of stroke cell therapy into clinical practice. The goal of this work was to quantitatively assess the impact of brain tissue perfusion on the distribution of IA transplanted MSCs in rat brains. We performed a selective MR-perfusion study with bolus IA injection of gadolinium-based contrast agent and subsequent IA transplantation of MSCs in intact rats and rats with experimental stroke and evaluated the correlation between different perfusion parameters and cell distribution estimated by susceptibility weighted imaging (SWI) immediately after cell transplantation. The obtained results reve...

Nucleic Acid Therapeutics, 2021

A series of 2'-deoxy and novel 2'-O-methyl and 2'-O-(2-methoxyethyl) (2'-MOE) oligonucleotides wi... more A series of 2'-deoxy and novel 2'-O-methyl and 2'-O-(2-methoxyethyl) (2'-MOE) oligonucleotides with internucleotide methanesulfonyl (mesyl, μ) or 1butanesulfonyl (busyl, β) phosphoramidate groups have been synthesized for evaluation as potential splice-switching oligonucleotides. Evaluation of their spliceswitching activity in spinal muscular atrophy (SMA) patient derived fibroblasts revealed no significant difference in splice-switching efficacy between 2'-MOE mesyl oligonucleotide and the corresponding phosphorothioate (nusinersen). Yet, a survival study with model neonatal mice have shown the antisense 2'-MOE mesyl oligonucleotide to be inferior to nusinersen at the highest dose of 40 mg/kg. A reason for their lower activity in vivo as ascertained by cellular uptake study via fluorescent confocal microscopy in HEK293 cell line could possibly be ascribed to compromised endosomal release and/or nuclear uptake of the 2'-OMe or 2'-MOE μand β-oligonucleotides as compared to their phosphorothioate analog.

Frontiers in Neuroscience, 2021

Cell therapy is an emerging approach to stroke treatment with a potential to limit brain damage a... more Cell therapy is an emerging approach to stroke treatment with a potential to limit brain damage and enhance its restoration after the acute phase of the disease. In this study we tested directly reprogrammed neural precursor cells (drNPC) derived from adult human bone marrow cells in the rat middle cerebral artery occlusion (MCAO) model of acute ischemic stroke using human placenta mesenchymal stem cells (pMSC) as a positive control with previously confirmed efficacy. Cells were infused into the ipsilateral (right) internal carotid artery of male Wistar rats 24 h after MCAO. The main goal of this work was to evaluate real-time distribution and subsequent homing of transplanted cells in the brain. This was achieved by performing intra-arterial infusion directly inside the MRI scanner and allowed transplanted cells tracing starting from their first pass through the brain vessels. Immediately after transplantation, cells were observed in the periphery of the infarct zone and in the bra...

Cellular and Molecular Life Sciences, 2020

Fluorescent proteins are commonly used to label target proteins in live cells. However, the conve... more Fluorescent proteins are commonly used to label target proteins in live cells. However, the conventional approach based on covalent fusion of targeted proteins with fluorescent protein probes is limited by the slow rate of fluorophore maturation and irretrievable loss of fluorescence due to photobleaching. Here we report a genetically encoded protein labeling system utilizing transient interactions of small, 21-28 residues-long helical protein tags (K/E coils, KEC). In this system, a protein of interest, covalently tagged with a single coil, is visualized through binding to a cytoplasmic fluorescent protein carrying a complementary coil. The reversible heterodimerization of KECs, whose affinity can be tuned in a broad concentration range from nanomolar to micromolar, allows continuous exchange and replenishment of the tag bound to a targeted protein with the entire cytosolic pool of soluble fluorescent coils. We found that, under conditions of partial illumination of living cells, the photostability of labeling with KECs exceeds that of covalently fused fluorescent probes by approximately one order of magnitude. Similarly, single molecule localization microscopy with KECs provided higher labeling density and allowed a

ACS Nano, 2019

Liposomes are the most extensively used nanocarriers in cancer therapy. Despite the advantages th... more Liposomes are the most extensively used nanocarriers in cancer therapy. Despite the advantages these vehicles provide over free drug there are still limitations with regards to the efficiency of liposomes delivery to tumors and off-target accumulation. A better understanding of nanodrugs extravasation mechanisms in different tumor types and normal vessels is needed to improve their antitumor activity. We used intravital microscopy to track for fluorescent liposomes behavior in xenograft tumor models (murine breast cancer 4T1 and melanoma B16, human prostate cancer 22Rv1) and normal skin and identified two distinct extravasation patterns. Microleakage, a local perivascular nanoparticle deposition, was found both in malignant and healthy tissues. This type of liposomes leakage does not provide access to tumor cells and is presumably responsible for drug deposition in normal tissues. In contrast, macroleakage penetrated deep into tissues and localized predominantly on the tumor-host interface. Although neutrophils did not uptake liposomes their extravasation appeared to initiate both micro- and macroleakages. Based on neutrophils and liposomes extravasation dynamics we hypothesized that microleakage and macroleakage are subsequent steps of the extravasation process corresponding to liposomes transport through endothelial and subendothelial barriers. Of note, extravasation spots were detected more often in the proximity of neutrophils, and across studied tumor types neutrophils counts correlated with leakage frequencies. Reduced liposomes accumulation in 4T1 tumors upon Ly6G depletion further corroborated neutrophils role in nanoparticles delivery. Elucidating liposomes extravasation routes has a potential to help improve existing strategies and develop effective nanodrugs for cancer therapy.

Russian Journal of Transplantology and Artificial Organs, 2019

Aim. Neural progenitor cells (NPC) are used for the development of cell therapies of neurological... more Aim. Neural progenitor cells (NPC) are used for the development of cell therapies of neurological diseases. Their stereotaxic transplantation in the middle cerebral artery occlusion (MCAO) model imitating ischemic stroke results in symptom aleviation. However, exploration of less invasive transplantation options is essential, because stereotaxic transplantation is a complex procedure and can be applied to humans only by vital indications in a specialized neurological ward. The aim of the present study was to evaluate the efficacy of cell therapy of the experimental ischemic stroke by the intra-arterial transplantation of NPC.Materials and methods. NPC for transplantation (IPSC-NPC) were derived by two-stage differentiation of cells of a stable line of human induced pluripotent stem cells. Stroke modeling in rats was carried out by transitory 90 min endovascular MCAO by a silicon-tipped filament. NPC were transplanted 24 hours after MCAO. Repetitive magnetic resonance tomography of e...

НАНОМЕДИЦИНА, 2018

Травма спинного мозга (ТСМ) - это травматическое повреждение, не являющееся следствием заболевани... more Травма спинного мозга (ТСМ) - это травматическое повреждение, не являющееся следствием заболевания. Мезенхимальные стволовые клетки (МСК) становятся одним из наиболее используемых типов стволовых клеток как в научных исследованиях, так и в клинических испытаниях. С учетом предыдущих работ, в которых использовали от 4 x 105 до 1 x 106 клеток, целью данного исследования было определить количество МСК, оптимальное для трансплантации при хронической ТСМ. Магнитные наночастицы (НЧ) использовали для доказательства точности проведенной трансплантации. С помощью магнитно-резонансной томографии (МРТ), диффузионно-тензорной визуализации (DTI), диффузионно-тензорной трактографии (DTT) и поведенческих тестов мы проверили влияние различного количества МСК на уменьшение пораженной полости и посттравматического свища, подавление формирования глиального рубца, усиление ремоделирования нейронных волокон, содействие регенерации и прорастанию аксонов, улучшение васкуляризации, повышение уровня экспрес...

Scientific reports, Jan 26, 2018

High-quality, 25 nm octahedral-shaped FeO magnetite nanocrystals are epitaxially grown on 9 nm Au... more High-quality, 25 nm octahedral-shaped FeO magnetite nanocrystals are epitaxially grown on 9 nm Au seed nanoparticles using a modified wet-chemical synthesis. These FeO-Au Janus nanoparticles exhibit bulk-like magnetic properties. Due to their high magnetization and octahedral shape, the hybrids show superior in vitro and in vivo T relaxivity for magnetic resonance imaging as compared to other types of FeO-Au hybrids and commercial contrast agents. The nanoparticles provide two functional surfaces for theranostic applications. For the first time, FeO-Au hybrids are conjugated with two fluorescent dyes or the combination of drug and dye allowing the simultaneous tracking of the nanoparticle vehicle and the drug cargo in vitro and in vivo. The delivery to tumors and payload release are demonstrated in real time by intravital microscopy. Replacing the dyes by cell-specific molecules and drugs makes the FeO-Au hybrids a unique all-in-one platform for theranostics.

Molecular Pharmaceutics, 2016

Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which i... more Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which is the most frequent and aggressive types, is one of the important objectives in nanomedicine. Vascular endothelial growth factor (VEGF) and its receptor type II (VEGFR2) are promising targets, because they are overexpressed by not only core cells but also by migrated glioma cells, which are responsible for resistance and rapid progression of brain tumors. The purpose of the present study was to develop the liposomal drug delivery system combining enhanced loading capacity of cisplatin and high binding affinity to glioma cells. This was achieved by using of highly soluble cisplatin analog, cis-diamminedinitratoplatinum(II), and antibodies against the native form of VEGF or VEGFR2 conjugated to liposome surface. The developed drug delivery system revealed sustained drug release profile, high affinity to antigens as well as increased uptake by glioma C6 and U-87 MG cells. Pharmacokinetic study on glioma C6-bearing rats revealed prolonged blood circulation time of the liposomal formulation. The above features enabled the present drug delivery system to overcome both poor pharmacokinetics typical for Page 2 of 44 ACS Paragon Plus Environment Molecular Pharmaceutics 3 platinum formulations and low loading capacity typical for conventional liposomal cisplatin formulations.

Bulletin of experimental biology and medicine, 2014

The aim of this study was to create a nanocontainer conjugated with monoclonal antibodies to conn... more The aim of this study was to create a nanocontainer conjugated with monoclonal antibodies to connexin 43 (Cx43) that is actively expressed at the periphery of C6 glioma and in the astroglia roll zone. Stable vector nanogels with high (up to 35%) cisplatin load were synthesized. The antitumor effects of Cx43-modified cisplatin-loaded nanogels, free cisplatin, and nonspecific drugs were carried out on C6 glioma model. Vector nanogels reduced systemic toxicity of cisplatin, effectively inhibited tumor growth, and significantly prolonged the lifespan of animals with experimental tumors.

Drug Delivery, 2014

Targeted drug delivery for brain tumor treatment is one of the important objectives in nanomedici... more Targeted drug delivery for brain tumor treatment is one of the important objectives in nanomedicine. Human glioblastoma is the most frequent and aggressive type of brain tumors. The preferential expression of membrane protein connexin 43 (Cx43) and brain-specific anion transporter (BSAT1) in the tumor and peritumoral area is a key component for targeted drug delivery. The purpose of this study was to design cisplatin-loaded nanogels conjugated with monoclonal antibodies to Cx43 and BSAT1 for treatment of intracranial gliomas 101/8. MRI volumetric analysis of tumor-bearing rats indicated significantly reduced tumor volume with cisplatin-loaded targeted-nanogel treatment compared to other formulations. The median survival of rats treated with targeted nanogels conjugated with specific mAbs against extracellular loops of Cx43 and BSAT1 were 27 and 26.6 days higher than that in control group, respectively. For the first time we demonstrated the efficiency of mAb-targeted cisplatin-loaded nanogels in the experimental model of glioma 101/8. This approach could facilitate the development of new drug delivery systems for the treatment of gliomas.

International Journal of Molecular Sciences

Predicting the ability of nanoparticles (NP) to access the tumor is key to the success of chemoth... more Predicting the ability of nanoparticles (NP) to access the tumor is key to the success of chemotherapy using nanotherapeutics. In the present study, the ability of the dual NP-based theranostic system to accumulate in the tumor was evaluated in vivo using intravital microscopy (IVM) and MRI. The system consisted of model therapeutic doxorubicin-loaded poly(lactide-co-glycolide) NP (Dox-PLGA NP) and novel hybrid Ce3/4+-doped maghemite NP encapsulated within the HSA matrix (hMNP) as a supermagnetic MRI contrasting agent. Both NP types had similar sizes of ~100 nm and negative surface potentials. The level of the hMNP and PLGA NP co-distribution in the same regions of interest (ROI, ~2500 µm2) was assessed by IVM in mice bearing the 4T1-mScarlet murine mammary carcinoma at different intervals between the NP injections. In all cases, both NP types penetrated into the same tumoral/peritumoral regions by neutrophil-assisted extravasation through vascular micro- and macroleakages. The maxi...

Biomedicines

Glucose and lipid metabolism are crucial functional systems in eukaryotes. A large number of expe... more Glucose and lipid metabolism are crucial functional systems in eukaryotes. A large number of experimental studies both in animal models and humans have shown that long non-coding RNAs (lncRNAs) play an important role in glucose and lipid metabolism. Previously, human lncRNA DEANR1/linc00261 was described as a tumor suppressor that regulates a variety of biological processes such as cell proliferation, apoptosis, glucose metabolism and tumorigenesis. Here we report that murine lncRNA Falcor/LL35, a proposed functional analog of human DEANR1/linc00261, is predominantly expressed in murine normal hepatocytes and downregulated in HCC and after partial hepatectomy. The application of high-throughput approaches such as RNA-seq, LC-MS proteomics, lipidomics and metabolomics analysis allowed changes to be found in the transcriptome, proteome, lipidome and metabolome of hepatocytes after LL35 depletion. We revealed that LL35 is involved in the regulation of glycolysis and lipid biosynthesis ...

Pharmaceutics, 2021

Fluorescently labeled nanoparticles are widely used for evaluating their distribution in the biol... more Fluorescently labeled nanoparticles are widely used for evaluating their distribution in the biological environment. However, dye leakage can lead to misinterpretations of the nanoparticles’ biodistribution. To better understand the interactions of dyes and nanoparticles and their biological environment, we explored PLGA nanoparticles labeled with four widely used dyes encapsulated (coumarin 6, rhodamine 123, DiI) or bound covalently to the polymer (Cy5.5.). The DiI label was stable in both aqueous and lipophilic environments, whereas the quick release of coumarin 6 was observed in model media containing albumin (42%) or liposomes (62%), which could be explained by the different affinity of these dyes to the polymer and lipophilic structures and which we also confirmed by computational modeling (log PDPPC/PLGA: DiI—2.3, Cou6—0.7). The importance of these factors was demonstrated by in vivo neuroimaging (ICON) of the rat retina using double-labeled Cy5.5/Cou6-nanoparticles: encapsula...

NEUROSCIENCE FOR MEDICINE AND PSYCHOLOGY, 2021

NEUROSCIENCE FOR MEDICINE AND PSYCHOLOGY, 2021