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Radical polymerization was used to synthesize and characterize (co)polymers with sodium styrenesulfonate (NaSS), 4-methacryloylamidosalicylic acid (MASA), and

Water-soluble terpolymers of 2-deoxy-N-methacryloylamidoglucose, methacryloylacetone, and methacrylic acid have been synthesized by the of radical copolymerization method. It has been shown that they form luminescent complexes with terbium ions in aqueous solutions. The luminescence intensity depends on the ratio of the components and remains constant in the presence of CaCl2 and NaCl. These terbium-binding terpolymers can be the basis for the creation of both luminescent probes and radioactive pharmaceuticals where a short-lived γ-emitter 161Tb is used for cancer ratiotherapy.

Polysaccharide-based polyelectrolyte complexes (PECs) are of great interest for the development of drug delivery systems, as they are easily prepared and exhibit a wide range of colloidal properties. The water-soluble diethylaminoethyl chitosan (DEAE-CS) was synthesized with various degrees of substitution (DS), ranging from 26 to 113%. Analysis of the substitution pattern of DEAE-CS by different NMR techniques revealed N- and O-substitution, as well as quaternization of the tertiary amino group of the DEAE substituent; the fraction of quaternary amino groups increased with the DS. Unlike the tertiary amino groups, the quaternary amino groups did not support increases in the ζ-potential of DEAE-CS with the DS and the complexation with hyaluronic acid (HA). The influence of the PEC composition, DS of DEAE-CS, and mixing order on the size and polydispersity of PEC nanoparticles was investigated by dynamic and static light scattering. Internal disordered heterogeneous PEC nanoparticles were formed by the aggregates of several primary PECs. Disordered and structurally heterogeneous spherical complexes were formed (Rg/Rh = 1.0 ± 0.3). The obtained PECs were metastable and their properties were influenced by mixing order. The high molecular weight component (HA), being a minor component, was more exposed on the surface than was the low molecular weight DEAE-CS.

The development of nanotechnology-based antibiotic delivery systems (nanoantibiotics) is an important challenge in the effort to combat microbial multidrug resistance. These systems have improved biopharmaceutical characteristics by increasing local bioavailability and reducing systemic toxicity and the number and frequency of drug side effects. Conjugation of low -molecular -weight antibacterial agents with natural polysaccharides is an effective strategy for developing optimal targeted delivery systems with programmed release and reduced cytotoxicity. This study describes the synthesis of conjugates of colistin (CT) and hyaluronic acid (HA) using carbodiimide chemistry to conjugate the amino groups of CT with the carboxyl groups of HA. The obtained polysaccharide carriers had a degree of substitution (DS) with CT molecules of 3-10 %, and the CT content was 129-377 μg/mg. The size of the fabricated particles was 300-600 nm; in addition, there were conjugates in the form of single macromolecules (30-50 nm). The ζ-potential of developed systems was about -20 mV. In vitro release studies at pH 7.4 and pH 5.2 showed slow hydrolysis of amide bonds, with a CT release of 1-5 % after 24 h. The conjugates retained antimicrobial activity depending on the DS: at DS 8 %, the minimum inhibitory concentration (MIC) of the conjugate corresponded to the MIC of free CT. The resulting systems also reduced CT nephrotoxicity by 20-50 %. These new conjugates of CT with HA are promising for the development of nanodrugs for safe and effective antimicrobial therapy.

The growth of microbial multidrug resistance is a problem in modern clinical medicine. Chemical modification of active pharmaceutical ingredients is an attractive strategy to improve their biopharmaceutical properties by increasing bioavailability and reducing drug toxicity. Conjugation of antimicrobial drugs with natural polysaccharides provides high efficiency of these systems due to targeted delivery, controlled drug release and reduced toxicity. This paper reports a two-step synthesis of colistin conjugates (CT) with succinyl chitosan (SucCS); first, we modified chitosan with succinyl anhydride to introduce a carboxyl function into the polymer molecule, which was then used for chemical grafting with amino groups of the peptide antibiotic CT using carbodiimide chemistry. The resulting polymeric delivery systems had a degree of substitution (DS) by CT of 3–8%, with conjugation efficiencies ranging from 54 to 100% and CT contents ranging from 130–318 μg/mg. The size of the obtained particles was 100–200 nm, and the ζ-potential varied from −22 to −28 mV. In vitro release studies at pH 7.4 demonstrated ultra-slow hydrolysis of amide bonds, with a CT release of 0.1–0.5% after 12 h; at pH 5.2, the hydrolysis rate slightly increased; however, it remained extremely low (1.5% of CT was released after 12 h). The antimicrobial activity of the conjugates depended on the DS. At DS 8%, the minimum inhibitory concentration (MIC) of the conjugate was equal to the MIC of native CT (1 µg/mL); at DS of 3 and 5%, the MIC increased 8-fold. In addition, the developed systems reduced CT nephrotoxicity by 20–60%; they also demonstrated the ability to reduce bacterial lipopolysaccharide-induced inflammation in vitro. Thus, these promising CT-SucCS conjugates are prospective for developing safe and effective nanoantibiotics.

Nanotechnology-based modification of known antimicrobial agents is a rational and straightforward way to improve their safety and effectiveness. The aim of this study was to develop colistin (CT)-loaded polymeric carriers based on hyaluronic acid (HA) for potential application as antimicrobial agents against multi-resistant gram-negative microorganisms (including ESKAPE pathogens). CT-containing particles were obtained via a polyelectrolyte interaction between protonated CT amino groups and HA carboxyl groups (the CT-HA complex formation constant [logKCT-HA] was about 5.0). The resulting polyelectrolyte complexes had a size of 210–250 nm and a negative charge (ζ-potential −19 mV), with encapsulation and loading efficiencies of 100% and 20%, respectively. The developed CT delivery systems were characterized by modified release (45% and 85% of CT released in 15 and 60 min, respectively) compared to pure CT (100% CT released in 15 min). In vitro tests showed that the encapsulation of CT in polymer particles did not reduce its pharmacological activity; the minimum inhibitory concentrations of both encapsulated CT and pure CT were 1 μg/mL (against Pseudomonas aeruginosa).

Copolymers of 4-acryloylmorpholine with 2-dimethyl- and 2-diethylaminoethyl methacrylates of variable composition and molecular mass were prepared by free-radical copolymerization. The reactivity ratios of the comonomers were determined for the first time. The copolymers synthesized are capable to reduce Ag+ ions without using additional agents to form stable nanodispersions of zerovalent silver with spherical nanoparticles of 8–10 nm size.

A practical protocol has been designed to synthesize dendronized polymeric chelating agents containing 1,4,7,10-tetraazacyclodocecane-N,N′,N″,N′″-tetraacetic acid (DOTA) ligand. The efficiency of suggested approach was verified by grafting of N-vinylpyrrolidone-acrolein P(VP-Ac) copolymer with dendrons containing several DOTA residues as compared to acylation of N-vinylpyrrolidone-vinylamine P(VP-VA) copolymer with active ester of DOTA. It was shown that attachment of pre-synthesized branched building blocks using hydrazone ligation strategy is an efficient method to increase the payload of carrier molecule. A similar methodology was applied for the preparation of polymer grafted by dendrons bearing DOTA complexes with paramagnetic ions (Gd3+ and Mn2+). Obtained results evidenced that polymer-metal complexes possess high relaxivity values and can be considered as promising candidates for MRI contrast agents. The presented results demonstrate utility of hydrazone ligation strategy for the synthesis and screening of dendronized polymeric carriers of different nature.

Poly( l -lactide) and poly( d , l -lactide) samples have been synthesized through ring-opening polymerization. The homological series of two poly(lactide)s have been studied in 1,4-dioxane solutions by a complex of methods: molecular hydrodynamics, molecular optics, NMR, and optical rotation. The 1 H and 13 C NMR spectroscopy and optical rotation proved the different stereo isomeric composition of poly( l -lactide) and poly( d , l -lactide) polymer series. The P- l -LA series are isotactic polymers, whereas the P- d , l -LA polymer series are atactic or syndiotactic ones. The hydrodynamic volume of poly( l -lactide) macromolecules was found to be larger than that for poly( d , l -lactide) macromolecules. Hydrodynamic studies were performed for P- l -LA series in the range of molar masses: 3.5 M × 10 −3 , g/mol d , l -LA series in the range: 1.6 M × 10 −3 , g/mol l -lactide chains in solution exhibit higher equilibrium rigidity than poly- d , l -lactide chains, which is explained by different chain tacticity. For the first time the birefringence of solution of two investigated types of poly(lactide) macromolecules in mechanical and electrical fields was studied. Both birefringence methods demonstrate the net differences between optical properties of P- l -LA and P- d , l -LA chains and confirm the conclusion made from the hydrodynamic study. Comparisons with the literature data concerning intrinsic viscosity values and chain rigidity parameters have been made.

In this work, a method to prepare hybrid amphiphilic block copolymers consisting of biocompatible synthetic glycopolymer with non-degradable backbone and biodegradable poly(amino acid) (PAA) was developed. The glycopolymer, poly(2-deoxy-2-methacrylamido-D-glucose) (PMAG), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Two methods for modifying the terminal dithiobenzoate-group of PMAG was investigated to obtain the macroinitiator bearing a primary aliphatic amino group, which is required for ring-opening polymerization of N-carboxyanhydrides of hydrophobic &alpha, amino acids. The synthesized amphiphilic block copolymers were carefully analyzed using a set of different physico-chemical methods to establish their composition and molecular weight. The developed amphiphilic copolymers tended to self-assemble in nanoparticles of different morphology that depended on the nature of the hydrophobic amino acid present in the copolymer. The hydrodynamic diameter, morphology, and cytotoxicity of polymer particles based on PMAG-b-PAA were evaluated using dynamic light scattering (DLS) and transmission electron microscopy (TEM), as well as CellTiter-Blue (CTB) assay, respectively. The redox-responsive properties of nanoparticles were evaluated in the presence of glutathione taken at different concentrations. Moreover, the encapsulation of paclitaxel into PMAG-b-PAA particles and their cytotoxicity on human lung carcinoma cells (A549) and human breast adenocarcinoma cells (MCF-7) were studied.

Nanovaccines based on superparamagnetic iron oxide nanoparticles (SPIONs) provide a novel approach to induce the humoral and cell-based immune system to fight cancer. Herein, we increased the immunostimulatory capacity of SPIONs by coating them with recombinant heat shock protein 70 (Hsp70) which is known to chaperone antigenic peptides. After binding, Hsp70-SPIONs deliver immunogenic peptides from tumor lysates to dendritiс cells (DCs) and thus stimulate a tumor-specific, CD8+ cytotoxic T cell response. We could show that binding activity of Hsp70-SPIONs to the substrate-binding domain (SBD) is highly dependent on the ATPase activity of its nucleotide-binding domain NBD), as shown by (31)P NMR spectroscopy. Immunization of C6 glioma-bearing rats with DCs pulsed with Hsp70-SPIONs and tumor lysates resulted in a delayed tumor progression (as measured by MRI) and an increased overall survival. In parallel an increased IFNγ secretion were detected in the serum of these animals and immunohistological analysis of subsequent cryosections of the glioma revealed an enhanced infiltration of memory CD45RO+ and cytotoxic CD8+ T cells. Taken together the study demonstrates that magnetic nanocarriers such as SPIONs coated with Hsp70 can be applied as a platform for boosting anti-cancer immune responses.

Poly(L-lactic acid) and poly(D,L-lactic acid) samples have been synthesized through ring-opening polymerization. Studying homological series of two poly(lactic acids) by molecular hydrodynamics and optical methods has shown that poly-L-lactide chains in solution exhibit higher equilibrium rigidity than poly-D,L-lactide chains, which is explained by different chain tacticity.

Brain tumor targeting efficiency and biodistribution of the superparamagnetic nanoparticles conjugated with heat shock protein Hsp70 (SPION–Hsp70) were evaluated in experimental glioma model. Synthesized conjugates were characterized using the method of longitudinal nonlinear response of magnetic nanoparticles to a weak ac magnetic field with measurements of second harmonic of magnetization (NLR- M 2 ). Cellular interaction of magnetic conjugates was analyzed in 9L glioma cell culture. The biodistribution of the nanoparticles and their accumulation in tumors was assessed by the latter approach as well. The efficacy of Hsp70-conjugates for contrast enhancement in the orthotopic model of 9L glioma was assessed by MR imaging (11 T). Magnetic nanoparticles conjugated with Hsp70 had the relaxivity properties of the MR-negative contrast agents. Morphological observation and cell viability test demonstrated good biocompatibility of Hsp70-conjugates. Analysis of the T 2 -weighted MR scans in tumor-bearing rats demonstrated the high efficacy of Hsp70-conjugates in contrast enhancement of the glioma in comparison to non-conjugated nanoparticles. High contrast enhancement of the glioma was provided by the accumulation of the SPION–Hsp70 particles in the glioma tissue (as shown by the histological assay). Biodistribution analysis by NLR- M 2 measurements evidenced the many-fold increase (~40) in the tumor-to-normal brain uptake ratio in the Hsp70-conjugates treated animals. Biodistribution pattern of Hsp70-decorated nanoparticles differed from that of non-conjugated SPIONs. Coating of the magnetic nanoparticles with Hsp70 protein enhances the tumor-targeting ability of the conjugates that could be applied in the MR imaging of the malignant brain tumors.

The potential of 1H NMR spectroscopy for determining the constants of chain transfer to a symmetric bifunctional agent of reversible chain transfer and for studying the changes in the current concentrations of the initial and final agents formed during the replacement of one leaving group with a polymer (oligomeric) radical of the agents of reversible chain transfer during the homopolymerization of N-vinyl succinimide, the homopolymerization of vinyl acetate, and the copolymerization of 4-vinylpyridine and tert-butyl acrylate in the presence S,S-dibenzyltrithiocarbonate is studied. The correct calculation of the constants of chain transfer is shown to be possible only during agreement of the studied system with the taken scheme of polymerization with reversible chain transfer, a minimum contribution of side reactions, and signal separation that is sufficient for the quantitative analysis of initial and polymer (monosubstituted) agents of reversible chain transfer in the 1H NMR spectra. The lower limit of the constants of transfer to the polymer agents of reversible chain transfer is estimated, and the great efficiency of these agents in comparison to that of the initial low-molecular-mass ones is directly confirmed. A complex of necessary investigations to study any new polymerization system where the controlled radical homoand copolymerization with reversible chain transfer in the presence of symmetric trithiocarbonates occurs is performed.

Well-defined homopolymers of 2-deoxy-2-methacrylamido- d -glucose (MAG) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization using 4-cyanopentanoic acid-4-dithiobenzoate as chain transfer agent (CTA) and 2,2′-azobisisobutyronitrile (AIBN) as initiator. The effect of polymerization conditions such as molar ratio of RAFT agent to initiator and monomer to RAFT agent on conversion and molecular mass characteristics of prepared polymers was estimated. Kinetics of the polymerization under various reaction conditions was studied as a function of time and conversion using in situ 1H NMR spectroscopy. The living character of polymerization was demonstrated by carriyng out the further chain extension experiments using isolated PMAG-CTA as a macroRAFT agent. For that, the PMAG with higher molecular weight, as well as block copolymer with acrylic acid were synthesized and characterized using 1H NMR and SEC analysis. A novel amphiphilic copolymer representing a hybrid of glycopolymer and polypeptide fragments was synthesized using RAFT and ring-opening polymerization (ROP). In this case, dithiobenzoate end-group of PMAG was transformed via simultaneous reduction and in situ thiol capping reaction by cysteamine hydrochloride into amino functionality suitable for polymerization of N-carboxyanhydrides (NCA). Two block copolymers of MAG with poly- l -phenylalanine (PPhe) differed with hydrophobic block length were synthesized, characterized and used for preparation of particles via copolymer self-assembly. The hydrodynamic diameter, morphology and cytotoxicity of polymer particles based on PMAG-b-PPhe were evaluated using DLS, TEM and MTT-assay, respectively. Moreover, the encapsulation of model compound (fluorescent dye rhodamine 6G) inside PMAG-b-PPhe micelles, as well as its release, were also tested.

The stress-inducible 72 kDa heat shock protein Hsp70 is known to be expressed on the membrane of highly aggressive tumor cells including high-grade gliomas, but not on the corresponding normal cells. Membrane Hsp70 (mHsp70) is rapidly internalized into tumor cells and thus targeting of mHsp70 might provide a promising strategy for theranostics. Superparamagnetic iron oxide nanoparticles (SPIONs) are contrast negative agents that are used for the detection of tumors with MRI. Herein, we conjugated the Hsp70-specific antibody (cmHsp70.1) which is known to recognize mHsp70 to superparamagnetic iron nanoparticles to assess tumor-specific targeting before and after ionizing irradiation. In vitro experiments demonstrated the selectivity of SPION-cmHsp70.1 conjugates to free and mHsp70 in different tumor cell types (C6 glioblastoma, K562 leukemia, HeLa cervix carcinoma) in a dose-dependent manner. High-resolution MRI (11 T) on T(2)-weighted images showed the retention of the conjugates in the C6 glioma model. Accumulation of SPION-cmHsp70.1 nanoparticles in the glioma resulted in a nearly 2-fold drop of T*(2) values in comparison to non-conjugated SPIONs. Biodistribution analysis using NLR-M(2) measurements showed a 7-fold increase in the tumor-to-background (normal brain) uptake ratio of SPION-cmHsp70.1 conjugates in glioma-bearing rats in comparison to SPIONs. This accumulation within Hsp70-positive glioma was further enhanced after a single dose (10 Gy) of ionizing radiation. Elevated accumulation of the magnetic conjugates in the tumor due to radiosensitization proves the combination of radiotherapy and application of Hsp70-targeted agents in brain tumors.

Chaperone Hsp70 can activate adaptive immunity suggesting its possible application as an antitumor vaccine. To assess the therapeutic capacity of Hsp70 we administered purified chaperone into a C6 glioblastoma brain tumor and explored the viability and tumor size as well as interferon gamma (IFNγ) production and cytotoxicity of lymphocytes in the treated animals. Targeted intratumoral injection of Hsp70 resulted in its distribution within the area of glioblastoma, and caused significant inhibition of tumor progression as confirmed by magnetic resonance imaging. The delay in tumor growth corresponded to the prolonged survival of tumor-bearing animals of up to 31 days versus 20 days in control. Continuous administration of Hsp70 with an osmotic pump increased survival even further (39 days). Therapeutic efficacy was associated with infiltration to glioblastoma of NK cells (Ly-6c+) and T lymphocytes (CD3+, CD4+ and CD8+) as well as with an increase in the activity of NK cells (granzyme B production) and CD8+ T lymphocytes as shown by IFNγ ELISPOT assay. Furthermore, we found that Hsp70 treatment caused concomitantly, with a tenfold elevated IFNγ production, an increase in anti-C6 tumor cytotoxicity of lymphocytes. In conclusion, continuous intratumoral delivery of Hsp70 demonstrates high therapeutic potential and therefore could be applied in the treatment of glioblastoma.

In order to prepare polymeric contrast agents, various ways of modification of N-vinylpyrrolidone copolymers with vinylamine or acrolein with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid derivatives were investigated.

Water-soluble gadofullerene Gd@Ful with composition Gd3+@C82(OH) 3– (x ~ 20) was synthesized for theranostic study. Nanosuspensions of Gd@Ful were used for magnetic relaxation measurements in vitro and for magnetic resonance imaging of a rat with intracranially implanted C6 glioma. Gd@Ful was shown to reduce proton relaxation times in vitro and provide dual contrast of T 1- and T 2-weighted images in a rat brain tumor model after paramagnetic intravenous delivery. Magnetic relaxation times of water protons under action of Gd@Ful were strongly shortened due to cluster formation and increase of motional correlation times of protons in the vicinity of the fullerene cage. The Gd@Ful administration promoted the improvement of glioma contrast enhancement at T 2-weighted images due to accumulation of paramagnetic substance at the tumor site. The contrast efficiency of Gd@Ful corresponds to the characteristics of negative contrast agent. The Gd@Ful nanosuspension is shown to be a contrast enhancer with high anti-tumor therapeutic potency. The retention of the Gd@Ful in the tumor resulted in a 75 % increase in survival times of the tumor-bearing animals.

Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted attention in the past decades due to their possible applications in brain tumor therapy, imaging, or drug delivery.1,2 Since nanoparticles cross the blood–brain barrier (BBB), they could be applied in the development of novel therapeutic modalities. One of the most promising approaches is based on the application of localized hyperthermia, when magnetic nanoparticles (MNPs) absorb energy from alternating magnetic fields and transform this energy into heat.3,4 The efficacy of this method was demonstrated in numerous preclinical and clinical studies.5–9 Recently, Maier-Hauff et al,10 in a single-arm phase II study of intratumoral thermotherapy combined with external beam radiotherapy in patients with recurrent glioblastoma, showed significant increase in overall survival (up to 23.2 mo) in comparison with historical control of 14.6 months reported by Stupp et al.11 Currently, the delivery of MNPs is based on a direct intratumoral injection, which limits the clinical application of this method.10 Further improvement of tumor targeting by the SPIONs requires a special surface coating, which can provide the specificity of SPION delivery to the tumor cells in vivo.12 Thus, conjugation to the purified antibody that selectively binds to the epidermal growth factor receptor deletion mutant (EGFRvIII) present on glioblastoma cells significantly elevated the efficacy of the accumulation of MNPs in the tumor site.13 In the elegant study by Basel et al,7 the authors used cytotherapy-directed hyperthermia when MNPs were loaded into monocyte/macrophage-like cells, which have been shown to specifically migrate into the tumor. Further studies demonstrated that the therapeutic efficacy of local hyperthermia could be increased by combination with other methods, including use of various anticancer drugs.6,14 Thus, Fe3O4 MNPs combined with chemotherapy and hyperthermia could overcome the multidrug resistance in an in vivo model of leukemia.6 Earlier we developed MNPs with a size

Magnetic nanoparticles conjugated with epidermal growth factor (MNP-EGF conjugates) were investigated by magnetic resonance (MR) relaxometry, on-chip quasielastic light scattering and magnetophoresis in aqueous dispersions and by MR imaging in phantom and in vivo models. MNP-EGF conjugates were prepared by carbodiimide EGF bonding with NH2-dextran modified iron oxide MNPs. The coefficients of magnetic relaxation efficiency (R1,R2,R2*) of MNP-EGF conjugates appeared to be close to the values obtained for nonconjugated MNPs and are correlating with those characteristic for negative contrast agents for MR imaging. MNP-EGF conjugates demonstrated ability of targeting MNPs to EGF receptors in EGF-overexpressed tumors. The feasibility of the MNP-EGF conjugates in diagnostics of certain cancer types was studied by MR imaging using mouse tumor models. It has been shown that intravenous and subcutaneous administration of MNP-EGF conjugates provided an enhancement of MR imaging contrast at the areas of accumulated cancer cells in melanoma mice model.

A procedure for functionalization of the surface of multiwall carbon nanotubes, based on treatment of the nanofiller with a strong oxidant and 1-hexadecylamine and aimed to improve the compatibility of nanotubes with a polypropylene matrix, was examined. Variation of the mechanical and electrical properties of the composite fiber based on polypropylene in relation to the concentration of the modified nanotubes was studied.

On the basis of hydrophilic copolymers of N-vinylamides—N-vinylpyrrolidone and N-methyl-N-vinylacetamide—that contain carboxylic or activated ester groups, new polymeric β-cyclodextrin derivatives are synthesized via polymer-analogous transformations. Their solubility in water depends on the content of β-cyclodextrin and the types of hydrophilic and reactive comonomers.

International audience; The four first generations of dendrigraft poly-L-lysine have been studied in dimethylformamide (aprotic solvent) and in 0.2 M NaCl aqueous solutions by isothermal translation diffusion, 1H NMR and viscometry methods. The relationships between diffusion coefficient, intrinsic viscosity and molar mass have been determined for dendrigraft poly-L-lysines, and the scaling index values have been compared to classical trifunctional dendrimers. Dendrimers and dendrigraft poly-L-lysines exhibited similitudes in their hydrodynamic behaviors. Nevertheless, dendrigraft poly-L-lysines displayed a specific behavior in solution. In contrast to dendrimers, a significant change of hydrodynamic dimension of dendrigraft poly-L-lysines according to the nature of the solvent has been observed. In aprotic solvent, the dendrigraft poly-L-lysine dimensions are about two times lower than in aqueous media (i.e., the hydrodynamic volume is contracted by a factor 8 in dimethylformamide), revealing the softness of dendrigraft poly-L-lysine compared to classical trifunctional dendrimers.

New cholesterol-containing water-soluble polymers based on N-methacryloyl aminoglucose and N-vinylpyrrolidone are synthesized by free-radical copolymerization and polymer-analogous transformations. Binary and ternary copolymers of various composition containing N-allylamine and N,N,N-trimethylaminoethyl methacrylate methyl sulfate units and cholesterol residues are prepared. Luminescently labeled copolymers of the same composition are obtained. Effects of the nature of polymers and the amount of cholesterol in them on the intramolecular mobility of macromolecules in solution are studied with polarized luminescence. When 2–4 mol % of cholesterol residues are incorporated into the copolymer, the intramolecular mobility of macromolecules decreases, thus indicating formation of intramolecular compact structures via interaction of nonpolar cholesterol groups. In copolymers containing charged groups, these structures are looser than those in neutral copolymers. It is shown that macromolecules of cholesterol-containing polymers of various types can interact with each other. 1 This work was supported by the Russian Foundation for Basic Research (project no. 08-03-00324) and the Council for Grants of the President of the Russian Federation for Support of Leading Institutes of Higher Education (NSh-4391.2008.3).

Multicentered initiators for the controlled (pseudoliving) radical polymerization are synthesized via polymer analog transformation of hydroxyl-containing polyimides based on o-aminophenols. Conditions providing variations in the degree of functionalization of polyimides by initiating 2-bromoisobutyrate groups are determined, and optimum conditions for the preparation of macroinitators containing the above groups in each repeat polyimide unit are found. Via the method of controlled radical polymerization with the atom transfer on multicentered macroinitiators in the presence of complexes of univalent copper halides, graft copolymers of poly(methylmethacrylate) on polyimide backbone are obtained. Molecular-mass characteristics of graft copolymers are studied via multiple-detection size-exclusion liquid chromatography. Preparation of graft copolymers (polymer brushes) with a homogeneous grafting density and a homogeneous length of side chains necessitates grafting of the side chain on the polyimide initiator, which contains initiating groups in each repeat unit.

An individual substance (20 mg/l) exhibiting phytotoxic properties, which, on the basis its spectral characteristics, was identified as zinniol, was obtained from the fungus Alternaria cirsinoxia. The nonspecific activity of this phytotoxin, with respect to plants of different families, was demonstrated. The minimum concentration (200 μg/ml) at which zinniol damages creeping thistle leaves and the median inhibition concentration (IC50) for rat embryonic fibroblasts (264 μg/ml) were determined.

New copolymers of the vinyl saccharide 2-deoxy-2-methacrylamido-D-glucose (M1) with acrylic and methacrylic (M2) acids differing in composition and molecular mass have been synthesized by free-radical copolymerization. The relative activities of the comonomers are determined. It is found that, for acrylic acid, r 1 = 3.03 ± 0.15 and r 2 = 0.5 ± 0.08 and, for methacrylic acid, r 1 = 1.070 ± 0.1 and r 2 = 1.18 ± 0.13. As is evidenced by potentiometric and viscometric measurements, the vinyl saccharide and acid units are capable of interacting, a circumstance that affects the conformational states of macromolecules.

Method for synthesis of graft-copolymers of a vinyl saccharide, 2-deoxy-2-methylacrylamido-D-glucose, and N,N-dimethylaminoethyl methacrylate was developed. Statistical copolymers with a controllable hydrophobic-hydrophilic balance were synthesized by alkylation of a statistical copolymer with various alkyl iodides.

Mercaptoacetylhydrazones of aliphatic and aromatic aldehydes exist in the solutions as tautomeric mixtures of open-chain and cyclic 1,3,4-thiadiazine forms. The linear hydrazone form consists of a set of isomers due to the configurational and conformational isomerism. At growing bulk of the alkyl substituent at the C=N bond of the aliphatic aldehydes derivatives decreases the fraction of the cyclic tautomer; therewith the logarithms of the constants of the chain-ring tautomeric equilibrium correlate with the steric constants of the alkyl substituents. In the series of the aromatic aldehydes mercaptoacetylhydrazones the linear tautomer prevails, and the equilibrium position is insignificantlyt affected at variation of the electronic characteristics of the substituents in the aromatic ring.

New polyvinylsaccharides containing primary or tertiary amino groups were synthesized by radical copolymerization of 2-deoxy-2-methacrylamido-D-glucose (MAG) with 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate (DEAEM), or allylamine hydrochloride. The reactivity ratios of comonomers were determined. The effect of copolymer composition on the conformational properties of macromolecules was detected. For MAG-DEAEM copolymers with DEAEM unit content more than 60 mol-% the increase of degree of ionization causes conformational transition at α = 0.3 to 0.7 from compact polymer coil to loose coil due to the electrostatic repulsion of charged amino groups. The increase of MAG content in copolymers is accompanied by a decrease of their cytotoxicity.

The paper discusses the scope for using the latest magnetic resonance techniques for determining major structure parameters of fibers based on macromolecular organic compounds. Particular attention is given to high-resolution methods for solids involving rotation at the magic angle, diffusion measurements, and magnetic resonance tomography.

The possibility of modifying the properties of poly(4,4′-oxydiphenylene)pyromellitimide films by introducing into prepolymer solutions nanoparticles of various compositions and structures [hydrosilicate nanoparticles in the form of layered structures (montmorillonite) and nanotubes; carbon nanofibers] was examined. New intercalating agents, tetranuclear aromatic diamines, were suggested for pretreatment of montmorillonite prior to introduction into heat-resistant polymers. The mechanical characteristics of the nanocomposites with hydrosilicate nanotubes can be optimized by chemical pretreatment of the nanotubes prior to introduction into the polymer matrix. Introduction of the above-named nanoparticles into the polymer matrix appreciably increases the elastic modulus of the material. The largest increase in the elastic modulus is observed with hydrosilicate nanotubes of the chrysotile structure, coated with an aromatic modifier.

Superparamagnetic iron-oxide based contrast agents can provide important diagnostic information regarding the assessment of cardiac inflammatory diseases. The aim of the study was to analyze whether nanoparticles conjugated to recombinant 70-kDa heat shock protein (Hsp70-SPION) can be applied for the detection of acute myocardium infarct by MRI. Cellular experiments demonstrated increased CD40-mediated uptake of Hsp70-SPIONs in comparison to non-conjugated SPIONs. Following induction of an acute infarct in rats by ligation of the left anterior descending artery SPIONs and Hsp70-SPION conjugates were injected intravenously on day 4. The animals underwent sequential MRI that showed the presence of the particles in the infarcted zone. Subsequent biodistribution analyses with the help of method on non-linear magnetic response indicated the preferential accumulation of the Hsp70-SPIONs in the heart tissue that was further confirmed with histological analyses. The study demonstrated that an acute infarct can be visualized by MRI using Hsp70-functionalized SPION conjugates.Superparamagnetic iron oxides nanoparticles (SPIONs) have been studied extensively as a contrast agent for MRI. Their tissue specificity can be further enhanced by conjugation with various ligands. In this study, the authors conjugated superparamagnetic nanoparticles to 70-kDa heat shock protein (Hsp70-SPION) to investigate the feasibility for the detection of acute myocardium infarct. The positive findings would suggest that this approach might be used clinically in the future.

A butylamine derivative of fullerene was prepared by the reaction of butylamine with fullerene C60. The experimental electrooptical and dipole characteristics of the derivative were compared with the corresponding calculated PM3 data. The reaction product proved to be inhomogeneous in the number of the amine molecules added; it contains polar multiadducts of C60 with noncentrosymmetric distribution of covalently bound amino groups over the fullerene core.

Cerebral edema commonly accompanies brain tumors and contributes to neurologic symptoms. The role of the interleukin-1 receptor antagonist conjugated to superparamagnetic iron oxide nanoparticles (SPION–IL-1Ra) was assessed to analyze its anti-edemal effect and its possible application as a negative contrast enhancing agent for magnetic resonance imaging (MRI). Rats with intracranial C6 glioma were intravenously administered at various concentrations of IL-1Ra or SPION–IL-1Ra. Brain peritumoral edema following treatment with receptor antagonist was assessed with high-field MRI. IL-1Ra administered at later stages of tumor progression significantly reduced peritumoral edema (as measured by MRI) and prolonged two-fold the life span of comorbid animals in a dose-dependent manner in comparison to control and corticosteroid-treated animals (P < .001). Synthesized SPION–IL-1Ra conjugates had the properties of negative contrast agent with high coefficients of relaxation efficiency. In vitro studies of SPION–IL-1Ra nanoparticles demonstrated high intracellular incorporation and absence of toxic influence on C6 cells and lymphocyte viability and proliferation. Retention of the nanoparticles in the tumor resulted in enhanced hypotensive T2-weighted images of glioma, proving the application of the conjugates as negative magnetic resonance contrast agents. Moreover, nanoparticles reduced the peritumoral edema confirming the therapeutic potency of synthesized conjugates. SPION–IL-1Ra nanoparticles have an anti-edemal effect when administered through a clinically relevant route in animals with glioma. The SPION–IL-1Ra could be a candidate for theranostic approach in neuro-oncology both for diagnosis of brain tumors and management of peritumoral edema.

Maxim A Shevtsov,1,2 Boris P Nikolaev,3 Ludmila Y Yakovleva,3 Anatolii V Dobrodumov,4 Anastasiy S Dayneko,5 Alexey A Shmonin,5,6 Timur D Vlasov,5 Elena V Melnikova,5 Alexander D Vilisov,4,5 Irina V Guzhova,1 Alexander M Ischenko,3 Anastasiya L Mikhrina,7 Oleg V Galibin,5 Igor V Yakovenko,2 Boris A Margulis1 1Institute of Cytology of the Russian Academy of Sciences (RAS), St Petersburg, Russia; 2AL Polenov Russian Research Scientific Institute of Neurosurgery, St Petersburg, Russia; 3Research Institute of Highly Pure Biopreparations, St Petersburg, Russia; 4Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS), St Petersburg, Russia; 5First St Petersburg IP Pavlov State Medical University, St Petersburg, Russia; 6Federal Almazov Medical Research Centre, St Petersburg, Russia; 7IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (RAS), St Petersburg, Russia Abstract: Recombinant 70 kDa heat shock protein (Hsp70) is an antiapoptotic protein that has a cell protective activity in stress stimuli and thus could be a useful therapeutic agent in the management of patients with acute ischemic stroke. The neuroprotective and neurotherapeutic activity of recombinant Hsp70 was explored in a model of experimental stroke in rats. Ischemia was produced by the occlusion of the middle cerebral artery for 45 minutes. To assess its neuroprotective capacity, Hsp70, at various concentrations, was intravenously injected 20 minutes prior to ischemia. Forty-eight hours after ischemia, rats were sacrificed and brain tissue sections were stained with 2% triphenyl tetrazolium chloride. Preliminary treatment with Hsp70 significantly reduced the ischemic zone (optimal response at 2.5 mg/kg). To assess Hsp70’s neurotherapeutic activity, we intravenously administered Hsp70 via the tail vein 2 hours after reperfusion (2 hours and 45 minutes after ischemia). Rats were then kept alive for 72 hours. The ischemic region was analyzed using a high-field 11 T MRI scanner. Administration of the Hsp70 decreased the infarction zone in a dose-dependent manner with an optimal (threefold) therapeutic response at 5 mg/kg. Long-term treatment of the ischemic rats with Hsp70 formulated in alginate granules with retarded release of protein further reduced the infarct volume in the brain as well as apoptotic area (annexin V staining). Due to its high neurotherapeutic potential, prolonged delivery of Hsp70 could be useful in the management of acute ischemic stroke. Keywords: focal ischemia, stroke, neuroprotection, neurotherapy, alginate granules

The coexistence in solution of tautomeric isoxazoline and pyrazoline forms of 1,3-alkanoylhydrazonoximes of acetylacetone has been detected and investigated by1H and13C NMR spectroscopic methods. The compounds indicated eliminate hydroxylamine under the action of acid catalysts, forming 1-acyl-3,5-dimethylpyrazoles.

Maxim A Shevtsov,1,2 Boris P Nikolaev,3 Ludmila Y Yakovleva,3 Yaroslav Y Marchenko,3 Anatolii V Dobrodumov,4 Anastasiya L Mikhrina,5 Marina G Martynova,1 Olga A Bystrova,1 Igor V Yakovenko,2 Alexander M Ischenko31Institute of Cytology of the Russian Academy of Sciences (RAS), 2AL Polenov Russian Scientific Research Institute of Neurosurgery, 3Research Institute of Highly Pure Biopreparations, 4Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS), 5IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (RAS), St Petersburg, RussiaAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs) conjugated with recombinant human epidermal growth factor (SPION–EGF) were studied as a potential agent for magnetic resonance imaging contrast enhancement of malignant brain tumors. Synthesized conjugates were characterized by transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance relaxometry. The interaction of SPION–EGF conjugates with cells was analyzed in a C6 glioma cell culture. The distribution of the nanoparticles and their accumulation in tumors were assessed by magnetic resonance imaging in an orthotopic model of C6 gliomas. SPION–EGF nanosuspensions had the properties of a negative contrast agent with high coefficients of relaxation efficiency. In vitro studies of SPION–EGF nanoparticles showed high intracellular incorporation and the absence of a toxic influence on C6 cell viability and proliferation. Intravenous administration of SPION–EGF conjugates in animals provided receptor-mediated targeted delivery across the blood–brain barrier and tumor retention of the nanoparticles; this was more efficient than with unconjugated SPIONs. The accumulation of conjugates in the glioma was revealed as hypotensive zones on T2-weighted images with a twofold reduction in T2 relaxation time in comparison to unconjugated SPIONs (P

Chaperone Hsp70 can activate adaptive immunity suggesting its possible application as an antitumor vaccine. To assess the therapeutic capacity of Hsp70 we administered purified chaperone into a C6 glioblastoma brain tumor and explored the viability and tumor size as well as interferon gamma (IFNγ) production and cytotoxicity of lymphocytes in the treated animals. Targeted intratumoral injection of Hsp70 resulted in its distribution within the area of glioblastoma, and caused significant inhibition of tumor progression as confirmed by magnetic resonance imaging. The delay in tumor growth corresponded to the prolonged survival of tumor-bearing animals of up to 31 days versus 20 days in control. Continuous administration of Hsp70 with an osmotic pump increased survival even further (39 days). Therapeutic efficacy was associated with infiltration to glioblastoma of NK cells (Ly-6c+) and T lymphocytes (CD3+, CD4+ and CD8+) as well as with an increase in the activity of NK cells (granzyme B production) and CD8+ T lymphocytes as shown by IFNγ ELISPOT assay. Furthermore, we found that Hsp70 treatment caused concomitantly, with a tenfold elevated IFNγ production, an increase in anti-C6 tumor cytotoxicity of lymphocytes. In conclusion, continuous intratumoral delivery of Hsp70 demonstrates high therapeutic potential and therefore could be applied in the treatment of glioblastoma.

The reaction of 5-hydroxy-3,3,5-trimethylisoxazolidine with methyl, ethyl, and tert-butyl acrylates, proceeds as Michael addition, and produces previously, unknown 5-hydroxy-3,3,5-trimethylisoxazolidine-2-propionic acid esters. The structures of the obtained products are proved by1H and13C NMR spectroscopy and by their subsequent transformation into 5-hydroxy-3,3,5-trimethylisoxazolidine-2-propionic acid.

An individual substance (20 mg/l) exhibiting phytotoxic properties, which, on the basis its spectral characteristics, was identified as zinniol, was obtained from the fungus Alternaria cirsinoxia. The nonspecific activity of this phytotoxin, with respect to plants of different families, was demonstrated. The minimum concentration (200 microg/ml) at which zinniol damages creeping thistle leaves and the median inhibition concentration (IC50) for rat embryonic fibroblasts (264 microg/ml) were determined.

The reaction of 5-hydroxy-3,3,5-trimethylisoxazolidine with methyl, ethyl, and tert-butyl acrylates, proceeds as Michael addition, and produces previously, unknown 5-hydroxy-3,3,5-trimethylisoxazolidine-2-propionic acid esters. The structures of the obtained products are proved by1H and13C NMR spectroscopy and by their subsequent transformation into 5-hydroxy-3,3,5-trimethylisoxazolidine-2-propionic acid.