N. V. Nukolova

Block ionomer complex micelles with cross-linked cores for drug delivery

Soft polymeric nanomaterials were synthesized by template-assisted method involving condensation of the poly(ethylene oxide)-b-polycarboxylate anions by metal ions into core-shell block ionomer complex micelles followed by chemical cross-linking of the polyion chains in the micelle cores. The resulting materials represent nanogels and are capable of swelling in a pH-dependent manner. The structural determinants that guide the self-assembly of the initial micelle templates and the swelling behavior of the cross-linked micelles include the block ionomer structure, the chemical nature of metal ions, the structure of the cross-links and the degree of cross-linking. The application of these materials for loading and release of a drug, cisplatin, is evaluated. These cross-linked block ionomer micelles have promise for delivery of pharmaceutical agents.

Core–shell–corona doxorubicin-loaded superparamagnetic Fe3O4 nanoparticles for cancer theranostics

Superparamagnetic iron oxide magnetic nanoparticles (MNPs) are successfully used as contrast agents in magnetic-resonance imaging. They can be easily functionalized for drug delivery functions, demonstrating great potential for both imaging and therapeutic applications. Here we developed new pH-responsive theranostic core-shell-corona nanoparticles consisting of superparamagentic Fe3O4 core that displays high T2 relaxivity, bovine serum albumin (BSA) shell that binds anticancer drug, doxorubicin (Dox) and poly(ethylene glycol) (PEG) corona that increases stability and biocompatibility. The nanoparticles were produced by adsorption of the BSA shell onto the Fe3O4 core followed by crosslinking of the protein layer and subsequent grafting of the PEG corona using monoamino-terminated PEG via carbodiimide chemistry. The hydrodynamic diameter, zeta-potential, composition and T2 relaxivity of the resulting nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis and T2-relaxometry. Nanoparticles were shown to absorb Dox molecules, possibly through a combination of electrostatic and hydrophobic interactions. The loading capacity (LC) of the nanoparticles was 8 wt.%. The Dox loaded nanoparticles release the drug at a higher rate at pH 5.5 compared to pH 7.4 and display similar cytotoxicity against C6 and HEK293 cells as the free Dox.

Visualization of experimental glioma C6 by MRI with magnetic nanoparticles conjugated with monoclonal antibodies to vascular endothelial growth factor.

We developed a method for obtaining iron oxide nanoparticles and their conjugation with monoclonal antibodies to vascular endothelial growth factor. The resultant vector nanoparticles were low-toxic and the antibodies retained their immunochemical activity after conjugation. The study was carried out on rats with intracranial glioma C6 on day 14 after its implantation. The intravenously injected nanoparticles visualized the brain tumor in contrast to nanoparticles conjugated with nonspecific immunoglobulins that did not accumulate in the tumor.

Targeted Delivery of Cisplatin by Сonnexin 43 Vector Nanogels to the Focus of Experimental Glioma C6

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.

Site-Directed Delivery of VEGF-Targeted Liposomes into Intracranial C6 Glioma

The efficiency of conventional chemotherapy for aggressive tumors in the CNS remains low and new strategies for the targeted delivery of anti-tumor substances are now actively developed. Pegylated liposomes covalently conjugated with monoclonal antibodies to VEGF synthesized by us are nanoparticle characterized by narrow size distribution and high dispersion stability. Immunochemical activity of antibodies after conjugation was 70% of initial level. The anti-VEGF liposomes developed by us were highly specific for VEGF+ tumor cells (in vitro and in vivo). Intravenous injection of VEGF-liposomes to rats with intracranial C6 glioma was followed by their specific accumulation in the malignant tissues and engulfment by glioma cells, which attested to target delivery and selective accumulation of anti-VEGF-liposomes in the brain tumor. Thus, the use of targeting molecules can significantly increase the distribution and efficiency of delivery of nanocontainers to a tumor characterized by hyperexpression of the target proteins.

Relationship between the Size of Magnetic Nanoparticles and Efficiency of MRT Imaging of Cerebral Glioma in Rats

BSA-coated Fe3O4 nanoparticles with different hydrodynamic diameters (36±4 and 85±10 nm) were synthesized, zeta potential and T2 relaxivity were determined, and their morphology was studied by transmission electron microscopy. Studies on rats with experimental glioma C6 showed that smaller nanoparticles more effectively accumulated in the tumor and circulated longer in brain vessels. Optimization of the hydrodynamic diameter improves the efficiency of MRT contrast agent.

Cuprizone Model as a Tool for Preclinical Studies of the Efficacy of Multiple Sclerosis Diagnosis and Therapy.

: To study demyelination and remyelination processes and their response to different drugs, a protocol for modeling multiple sclerosis using the copper chelator cuprizone was developed. Magnetic resonance imaging confirmed the presence of demyelination lesions on week 4 of 0.6% cuprizone-containing diet. Immunohistochemical staining with polyclonal antibodies to glial fibrillary acidic protein (pAb GFAP) confirmed the increase in the number of reactive astrocytes on week 4 of diet and during remyelination (week 2 after diet). Analysis of neurophysiological functions in mice with cuprizone-induced demyelination revealed motor and behavioral deficits. This model can be used as a tool for preclinical studies of the efficiency of multiple sclerosis diagnostic and therapy.

Magnetic Resonance Imaging of Tumors with the Use of Iron Oxide Magnetic Nanoparticles as a Contrast Agent

We studied the possibility of using BSA-coated magnetic iron oxide nanoparticles for magnetic resonance imaging diagnosis of C6 glioblastoma, 4T1 mammary adenocarcinoma, and RS-1 hepatic mucous carcinoma. In all three cases, magnetic nanoparticles accumulated in the tumor and its large vessels. Magnetic resonance imaging with contrast agent allows visualization of the tumor tissue and its vascularization.

Nanozyme technology at Moscow State University. Achievements and development perspectives

The work describes novel functional bionanosystems for treatment and diagnostics on the basis of proteins, enzymes, polymeric coatings, and magnetic nanoparticles developed at Lomonosov Moscow State University Laboratory for Chemical Design of Bionanomaterials in collaboration with scientists from UNC Eshelman School of Pharmacy (USA). The properties of enzymes (superoxide dismutase, catalase, organophosphate hydrolase, and lysines of bacteriophages) and other drug molecules immobilized in polymeric complexes, as well as the methods for targeted drug delivery using cell-mediated systems and magnetic nanoparticles in in vitro and in vivo operating conditions, are discussed. Physical and chemical characteristics, including data on the functional properties of the nanoformulations, are obtained. The nanoformulations developed demonstrated high potential therapeutic efficacy for the treatment of central nervous system and brain diseases, inflammations (including inflammatory diseases of the eye), cancer and infectious diseases, neurotoxic injury, and others. The possibilities of remote control biochemical reactions using a nonheating low-frequency alternating magnetic field (AMF) for the controlled release of drugs are analyzed in the review. The experimental results of the AMF effects on bionanosystems containing magnetic nanoparticles, such as changing the catalytic activities of enzymes bound to magnetic nanoparticles and ‘disordering’ of the lipid bilayer in membranes, are considered.

Internalization of Vectorized Liposomes Loaded with Plasmid DNA in C6 Glioma Cells

We studied internalization of vector nanocarriers loaded with plasmid DNA into C6 glioma cells. For improving selectivity of plasmid delivery, the liposomes were conjugated with monoclonal antibodies to VEGF and its receptor VEGFR2. Flow cytofluorometry and laser scanning confocal microscopy showed more intensive (more than 2-fold) internalization and accumulation of antibody-vectorized liposomes in C6 glioma cells in comparison with the control (liposomes conjugated with non-specific antibodies and non-vectorized liposomes). Using quantitative analysis of fluorescent signal, we showed that cationic immunoliposomes significantly more effective delivered pCop-Green-N plasmid DNA and ensured effective transfection of C6 glioma cells.