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1.
Dalton Trans ; 52(41): 15107-15114, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37814785

RESUMO

Ditopic di-o-quinone with a resorcinol bridge exhibits the ability to self-assemble in a reaction with copper, giving a cage-like binuclear complex that, due to the cofacially placed metal ions, is capable of encapsulation of different solvent molecules as guest ligands. Notably, the geometry of the internal cavity of this complex adjusts depending on the coordinating properties of the encapsulated molecule (mono- or bidentate). A feature of this species is that the cage-forming units are copper(II) bis-semiquinonate moieties, capable of undergoing ligand-centered redox transformations. Electrochemical and EPR spectroscopy studies showed that there is a channel for intramolecular electronic exchange interactions between the redox centres of the molecule.

2.
Materials (Basel) ; 16(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36676248

RESUMO

The effect of a promising method of performing a thermomechanical treatment which provides the nanocrystalline structure formation in bulk NiTi shape memory alloy samples and a corresponding improvement to their properties was studied in the present work. The bi-axial severe plastic deformation of Ti-50.7at.%Ni alloy was carried out on the MaxStrain module of the Gleeble system at 350 and 330 °C with accumulated true strains of e = 6.6-9.5. The obtained structure and its mechanical and functional properties and martensitic transformations were studied using DSC, X-ray diffractometry, and TEM. A nanocrystalline structure with a grain/subgrain size of below 80 nm was formed in bulk nickel-enriched NiTi alloy after the MaxStrain deformation at 330 °C with e = 9.5. The application of MaxStrain leads to the formation of a nanocrystalline structure that is characterized by the appearance of a nano-sized grains and subgrains with equiaxed and elongated shapes and a high free dislocation density. After the MaxStrain deformation at 330 °C with e = 9.5 was performed, the completely nanocrystalline structure with the grain/subgrain size of below 80 nm was formed in bulk nickel-enriched NiTi alloy for the first time. The resulting structure provides a total recoverable strain of 12%, which exceeds the highest values that have been reported for bulk nickel-enriched NiTi samples.

3.
Materials (Basel) ; 16(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36676351

RESUMO

In the present work, the possibility of manufacturing long-length TiNiHf rods with a lowered Hf content and a high-temperature shape memory effect in the range of 120-160 °C was studied. Initial ingots with 1.5, 3.0 and 5.0 at.% Hf were obtained by electron beam melting in a copper water-cooled stream-type mold. The obtained ingots were rotary forged at the temperature of 950 °C, with the relative strain from 5 to 10% per one pass. The obtained results revealed that the ingots with 3.0 and 5.0 at.% Hf demonstrated insufficient technological plasticity, presumably because of the excess precipitation of (Ti,Hf)2Ni-type particles. The premature destruction of ingots during the deformation process does not allow obtaining high-quality long-length rods. A long-length rod with a diameter of 3.5 mm and a length of 870 mm was produced by rotary forging from the ingot with 1.5 at.% Hf. The obtained TiNiHf rod had relatively high values of mechanical properties (a dislocation yield stress σy of 800 MPa, ultimate tensile strength σB of 1000 MPa, and elongation to fracture δ of 24%), functional properties (a completely recoverable strain of 5%), and a required finishing temperature of shape recovery of 125 °C in the as-forged state and of 155 °C after post-deformation annealing at 550 °C for 2 h.

4.
Membranes (Basel) ; 11(10)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34677500

RESUMO

The thermomechanical stability of the anion-cation exchange matrix "Polikon AC" on viscose nonwoven materials is investigated. In this work, a molecular model of a solvation environment for experimentally obtained "Polikon AC" mosaic membranes is refined. Mosaic membranes on a viscose fiber base were fabricated by the method of polycondensation filling. The temperature dependence of deformation was investigated for dry and wet anion and cation exchange membrane components at a constant tensile load of 1.5 N and a heating rate of 8 °C/min. The effect of moisture content on the deformation of anionite and cationite fragments under a constant external tensile load of 1.5 and 3 N in a temperature range up to 100 °C was studied.

5.
ACS Nano ; 15(7): 11341-11357, 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34250790

RESUMO

Safe application of nanoparticles in medicine requires full understanding of their pharmacokinetics including catabolism in the organism. However, information about nanoparticle degradation is still scanty due to difficulty of long-term measurements by invasive techniques. Here, we describe a magnetic spectral approach for in vivo monitoring of magnetic particle (MP) degradation. The method noninvasiveness has allowed performing of a broad comprehensive study of the 1-year fate of 17 types of iron oxide particles. We show a long-lasting influence of five parameters on the MP degradation half-life: dose, hydrodynamic size, ζ-potential, surface coating, and internal architecture. We observed a slowdown in MP biotransformation with an increase of the injected dose and faster degradation of the particles of a small hydrodynamic size. A comparison of six types of 100 nm particles coated by different hydrophilic polymer shells has shown that the slowest (t1/2 = 38 ± 6 days) and the fastest (t1/2 = 15 ± 4 days) degradations were achieved with a polyethylene glycol and polyglucuronic acid coatings, respectively. The most significant influence on the MP degradation was due to the internal architecture of the particles as the coverage of magnetic cores with a solid 39 nm polystyrene layer slowed down the half-life of the core-shell MPs from 48 days to more than 1 year. The revealed deeper insights into the particle degradation in vivo may facilitate rational design of nano- and microparticles with predictable long-term fate in vivo.


Assuntos
Nanopartículas , Polietilenoglicóis , Camundongos , Animais , Polímeros , Fenômenos Físicos , Fenômenos Magnéticos , Tamanho da Partícula
6.
Beilstein J Org Chem ; 17: 273-282, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33564336

RESUMO

The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox activity. An effective method for the synthesis of sterically hindered o-quinones containing 1,3-diketonate, dinitrile and p-quinone-methide functional groups at the periphery of the ligand has been developed. The novel compounds have rigid and conjugated structures and exhibit properties typical of o-quinones. A study of their monoreduced semiquinone derivatives reveal that the spin density is delocalized across the whole molecule, including peripheral fragments. The first stable o-quinone derivative bearing an annulated thiete heterocycle has been isolated and characterized.

7.
ACS Omega ; 5(50): 32792-32799, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33376917

RESUMO

It was found that the dicarbonyl-rhodium-o-semiquinonate complex (which thread-like crystals can bend reversibly under light/warm activation) can form two polymorphic modifications: isometric prisms (1) and sticks (2). Some thin sticks can bend as mentioned above. X-ray diffraction studies of polymorphic modifications at different temperatures were carried out. It was found that crystals 1 are destructed after cooling to 110 K as opposed to crystals 2. In turn, the reversible phase transition is detected in 2. In both polymorphic modifications, stack packaging motifs through the direct Rh-Rh bond are observed. The principal difference between packages of polymorphic modifications is that molecules 1 in the adjacent stacks are shifted relative to each other along the stack, in contrast to crystal 2. It was found that different packing of stacks leads to different anisotropic compression of crystals 1 and 2 during cooling, which is a key factor of their stability. Using the molecular invariom approach, the nature of the chemical bonds and charge distribution was investigated; the energy of the Rh-Rh bonds was estimated.

8.
ACS Omega ; 5(35): 22179-22191, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32923776

RESUMO

Novel sterically hindered catechols of the type 3-(RN=CH)-4,6-DBCatH2 with iminoalkyl or iminoaryl groups in the third position of the aromatic ring have been synthesized and characterized in detail. The o-benzoquinones 3-(RN=CH)-4,6-DBBQ have been synthesized by the oxidation of the corresponding catechols. The oxidation of methylimino-substituted catechol with K3[Fe(CN)6] in alkaline medium leads to the formation of two products: o-quinone and diene-dione, the product of the water addition to the corresponding o-quinone. Some o-benzoquinones react with water or methanol to yield products of water or methanol addition. A prototropic tautomerism is characteristic of catecholaldimines: a quinomethide form is observed in the case of aliphatic amine derivatives, while aryl-substituted catecholaldimines can exist both in the catechol and quinomethide forms in the crystalline state. The formation of dimeric structures motifs is observed in crystals. The electrochemical oxidation of imino-based catechols proceeds via two one-electron processes; the second wave is quasi-reversible, which is unusual for catechols.

9.
Inorg Chem ; 59(10): 6679-6683, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32368899

RESUMO

Especially grown crystals (elongated plates) of the complex (1,10-phen)Co(3,6-DBSQ)2 (1) reversibly elastically bend under laser excitation (532 or 808 nm) and/or heating in the temperature interval ∼242-265 K (1,10-phen = 1,10-phenanthroline, 3,6-DBSQ = anion-radical and 3,6-DBCat = dianion of 3,6-di-tert-butyl-o-benzoquinone). The abrupt interconversion of valence tautomers is observed in this temperature range: (phen)Co(3,6-DBCat)(3,6-DBSQ) ⇌ (phen)Co(3,6-DBSQ)2. Solving the problem of design of photo- (thermo-) actuators with preset parameters, the series of solid solutions of general formula (phen)x(bpy)1-xCo(3,6-DBSQ)2 was obtained and crystallized as thin elongated plates. Crystals of each solid solution demonstrate the maximal photomechanical response (bending) at a temperature close to its own valence tautomeric (VT) transition temperature. On the other hand, the VT transition temperature depends on the composition of the solid solution. So, by setting the composition of the solid solution, one can set the temperature of the photomechanical response. It is the first example of temperature-manageable photomechanical properties.

10.
Inorg Chem ; 59(10): 6774-6784, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32338505

RESUMO

The addition of different substituted o-benzoquinones and o-iminobenzoquinones to tin(II) bis(o-iminophenolates) of the types (Fc-IP)2SnII and (Fc-4,6-IP)2SnII (where Fc-IP is anion 2-(ferrocenylmethyleneamino)phenolate [Fc-C(H)═N(C6H4)O-] and Fc-4,6-IP is anion 2-(ferrocenylmethyleneamino)-4,6-di-tert-butylphenolate [Fc-C(H)═N(4,6-tBu-C6H2)O-]) in tetrahydrofuran leads to the oxidation of Sn(II) to Sn(IV) with formation of the corresponding tin(IV) catecholates (Fc-4,6-IP)2SnIV(3,6-Cat) (1), (Fc-IP)2SnIV(3,6-Cat) (2), (Fc-4,6-IP)2SnIV(4-Cl-3,6-Cat) (3), (Fc-IP)2SnIV(4-Cl-3,6-Cat) (4), (Fc-4,6-IP)2SnIV(4,5-Cl2-3,6-Cat) (5), and (Fc-IP)2SnIV(4,5-Cl2-3,6-Cat) (6) or the o-amidophenolates (Fc-4,6-IP)2SnIV(AP-Me) (7), (Fc-IP)2SnIV(AP-iPr) (8), and (Fc-4,6-IP)2SnIV(AP-iPr) (9). Here ligands 3,6-Cat, 4-Cl-3,6-Cat, and 4,5-Cl2-3,6-Cat are dianions 3,6-di-tert-butyl-, 4-chloro-3,6-di-tert-butyl-, and 4,5-dichloro-3,6-di-tert-butylcatecholates, respectively, and AP-Me and AP-iPr are dianions 4,6-di-tert-butyl-N-(2,6-dimethylphenyl)-o-amidophenolate and 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-amidophenolate, respectively. Complexes 1-9 have been characterized in detail by IR spectroscopy, cyclic voltammetry, and 1H, 13C, and 119Sn NMR spectroscopy. The molecular structures of tin(IV) complexes 5, 7, and 9 in the crystalline state were determined by single-crystal X-ray diffraction analysis. Complexes demonstrate a series of successive oxidations involving alternately catecholato/o-amidophenolato centers and ferrocenyl moieties. The relative oxidation potentials of these redox centers depend on the acceptor properties of the redox-active chelating O,O' or O,N ligand. An increase in the acceptor properties of redox-active o-quinonato-type ligands leads to an increase in the oxidation potentials of redox ligands as well as the following oxidation of ferrocenyl group(s). In two series of complexes, (Fc-4,6-L)2SnL' and (Fc-L)2SnL', where L' is AP-iPr, AP-Me, 3,6-Cat, 4-Cl-3,6-Cat, and 4,5-Cl2-3,6-Cat, a more pronounced convergence of the oxidation potentials of the redox-active o-quinonato ligand and ferrocenyl group occurs in the series (Fc-L)2SnL'.

11.
Molecules ; 25(8)2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32340382

RESUMO

The development of synthetic ways to fabricate nanosized materials with a well-defined shape, narrow-sized distribution, and high stability is of great importance to a rapidly developing area of nanotechnology. Here, we report an unusual reaction between amorphous two-line ferrihydrite and concentrated sulfuric or other mineral and organic acids. Instead of the expected dissolution, we observed the formation of new narrow-distributed brick-red nanoparticles (NPs) of hematite. Different acids produce similar nanoparticles according to scanning (SEM) and transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDX). The reaction demonstrates new possibilities for the synthesis of acid-resistant iron oxide nanoparticles and shows a novel pathway for the reaction of iron hydroxide with concentrated acids. The biomedical potential of the fabricated nanoparticles is demonstrated by the functionalization of the particles with polymers, fluorescent labels, and antibodies. Three different applications are demonstrated: i) specific targeting of the red blood cells, e.g., for red blood cell (RBC)-hitchhiking; ii) cancer cell targeting in vitro; iii) infrared ex vivo bioimaging. This novel synthesis route may be useful for the development of iron oxide materials for such specificity-demanding applications such as nanosensors, imaging, and therapy.


Assuntos
Ácidos/química , Materiais Biomédicos e Odontológicos , Compostos Férricos/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Materiais Biomédicos e Odontológicos/química , Humanos , Nanopartículas Magnéticas de Óxido de Ferro/ultraestrutura , Análise Espectral
12.
Molecules ; 25(3)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31979347

RESUMO

The reaction between the 2,2'-benzene-1,4-diylbis(6-hydroxy-4,7-di-tert-butyl-1,3-benzodithiol-2-ylium-5-olate triad (H2SQ) and the metallo-precursor [Yb(hfac)3]2H2O led to the formation of a dinuclear coordination complex of formula [Yb2(hfac)6(H2SQ)]0.5CH2Cl2 (H2SQ-Yb). After chemical oxidation of H2SQ in 2,2'-cyclohexa-2,5-diene-1,4-diylidenebis(4,7-di-tert-butyl-1,3-benzodithiole-5,6-dione (Q), the latter triad reacted with the [Yb(hfac)3]2H2O precursor to give the dinuclear complex of formula [Yb2(hfac)6(Q)] (Q-Yb). Both dinuclear compounds have been characterized by X-ray diffraction, DFT optimized structure and electronic absorption spectra. They behaved as field-induced Single-Molecule Magnets (SMMs) nevertheless the chemical oxidation of the semiquinone to quinone moieties accelerated by a factor of five the relaxation time of the magnetization of Q-Yb compared to the one for H2SQ-Yb. The H2SQ triad efficiently sensitized the YbIII luminescence while the chemical oxidation of H2SQ into Q induced strong modification of the absorption properties and thus a quenching of the YbIII luminescence for Q-Yb. In other words, both magnetic modulation and luminescence quenching are reached by the oxidation of the protonated semiquinone into quinone.


Assuntos
Imãs , Itérbio/química , Benzoquinonas/química , Química Computacional , Cristalografia por Raios X , Teoria da Densidade Funcional , Luminescência , Estrutura Molecular , Oxirredução , Quinonas/química , Espectrometria de Fluorescência , Temperatura , Difração de Raios X
13.
ACS Nano ; 14(2): 1792-1803, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-31944662

RESUMO

Smart materials that can switch between different states under the influence of chemical triggers are highly demanded in biomedicine, where specific responsiveness to biomarkers is imperative for precise diagnostics and therapy. Superior selectivity of drug delivery to malignant cells may be achieved with the nanoagents that stay "inert" until "activation" by the characteristic profile of microenvironment cues (e.g., tumor metabolites, angiogenesis factors, microRNA/DNA, etc.). However, despite a wide variety and functional complexity of smart material designs, their real-life applications are hindered by very limited sensitivity to inputs. Here, we present ultrasensitive smart nanoagents with input-dependent On/Off switchable affinity to a biomedical target based on a combination of gold nanoparticles with low-energy polymer structures. In the proposed method, a nanoparticle-based agent is surface coated with a custom designed flexible polymer chain, which has an input-switchable structure that regulates accessibility of the terminal receptor for target binding. Implementation of the concept with a DNA-model of such polymer has yielded nanoagents that have input-dependent cell-targeting capabilities and responsiveness to as little as 30 fM of DNA input in 15 min lateral flow assay. Thus, we show that surface phenomena can augment nanoagents with capability for switchable affinity without compromising the sensitivity to inputs. The proposed approach is promising for development of next-generation theranostic agents and ultrasensitive nanosensors for point-of-care diagnostics.


Assuntos
DNA/análise , Ouro/química , Nanopartículas Metálicas/química , Materiais Inteligentes/química , Sistemas de Liberação de Medicamentos , Tamanho da Partícula , Polímeros/química , Propriedades de Superfície
14.
Acta Biomater ; 103: 223-236, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31843718

RESUMO

Nanosized metal-organic frameworks (nMOFs) have shown great promise as high-capacity carriers for a variety of applications. For biomedicine, numerous nMOFs have been proposed that can transport virtually any molecular drug, can finely tune their payload release profile, etc. However, perspectives of their applications for the targeted drug delivery remain relatively unclear. So far, only a few works have reported specific cell targeting by nMOFs exclusively through small ligands such as folic acid or RGD peptides. Here we show feasibility of targeted drug delivery to specific cancer cells in vitro with nMOFs functionalized with such universal tool as an antibody. We demonstrate ca. 120 nm magnetic core/MOFs shell nanoagents loaded with doxorubicin/daunorubicin and coupled with an antibody though a hydrophilic carbohydrate interface. We show that carboxymethyl-dextran coating of nMOFs allows extensive loading of the drug molecules (up to 15.7 mg/g), offers their sustained release in physiological media and preserves antibody specificity. Reliable performance of the agents is illustrated with trastuzumab-guided selective targeting and killing of HER2/neu-positive breast cancer cells in vitro. The approach expands the scope of nMOF applications and can serve as a platform for the development of potent theranostic nanoagents. STATEMENT OF SIGNIFICANCE: The unique combination of exceptional drug capacity and controlled release, biodegradability and low toxicity makes nanosized metal-organic frameworks (nMOFs) nearly ideal drug vehicles for various biomedical applications. Unfortunately, the prospective of nMOF applications for the targeted drug delivery is still unclear since only a few examples have been reported for nMOF cell targeting, exclusively for small ligands. In this work, we fill the important gap and demonstrate nanoagent that can specifically kill target cancer cells via drug delivery based on recognition of HER2/neu cell surface receptors by such universal and specific tool as antibodies. The proposed approach is universal and can be adapted for specific biomedical tasks using antibodies of any specificity and nMOFs of a various composition.


Assuntos
Anticorpos/farmacologia , Sistemas de Liberação de Medicamentos , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/imunologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Nanopartículas de Magnetita/ultraestrutura , Estruturas Metalorgânicas/ultraestrutura
15.
Dalton Trans ; 48(28): 10516-10525, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31225849

RESUMO

A square-planar bis-o-semiquinonato nickel complex interacts with N,N'-disubstituted 1,4-diazabutadienes-1,3 forming six-coordinate compounds. The X-ray structural study indicates complex geometry to be close to the octahedral. Magnetic properties are determined by metal-ligand ferromagnetic exchange interactions which are promoted by complex geometry. In polar solvents (THF, CH2Cl2, and CHCl3) complexes are partly dissociated into corresponding diazabutadiene-nickel catecholate and free o-quinone. In the case of the most sterically hindered 1,4-bis-(2,6-di-iso-propylphenyl)-2,3-dimethyl-1,4-diazabutadiene-1,3 in n-hexane or toluene the above-mentioned reaction is accompanied by the coupling through the back-bonded methyl groups of diazabutadiene. The organic product of the coupling was eliminated from the complex, isolated and structurally characterized. Taking into account the quantitative yield the coupling reaction is the actual procedure for the synthesis of new potential nitrogen ligands.

16.
J Colloid Interface Sci ; 541: 143-149, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30685609

RESUMO

Exploration of novel types of iron oxide nanoparticles as well as novel versatile ways to prepare them in a controlled manner keeping in mind necessity of narrow size distributions and high colloidal and chemical stability is an important task for modern nanochemistry. Most of the procedures for preparation of nanocrystalline iron oxides require drastic conditions and complex mixtures of reagents, therefore there is a high demand for methods of synthesis of such nanoparticles (NPs) in mild conditions. In this study, we discovered a new way to prepare crystalline goethite-like hydrous ferric oxide (HFO) NPs by fast and simple precipitation procedure in aqueous media and probed modification strategies aimed at the development of modified HFO nanoparticles for biomedical applications, including express-diagnostics and specific cell targeting.


Assuntos
Neoplasias da Mama/metabolismo , Rastreamento de Células/métodos , Compostos Férricos/química , Compostos de Ferro/química , Minerais/química , Nanopartículas/administração & dosagem , Nanopartículas/química , Animais , Técnicas Biossensoriais , Neoplasias da Mama/patologia , Células CHO , Células Cultivadas , Cricetulus , Feminino , Humanos
17.
Inorg Chem ; 56(24): 14751-14754, 2017 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-29185722

RESUMO

Iminopyridine modified by TEMPO nitroxide was utilized for the synthesis of an octahedral bis(o-semiquinonato)cobalt complex. Variable-temperature magnetic susceptibility measurements detect a valence tautomeric transformation in the temperature range 200-300 K. A reproducible hysteresis loop of about 40 K width is observed on the magnetic moment temperature dependence in the transition region. Differential scanning calorimetry measurements confirm different temperatures of phase transitions accompanying a valence-tautomeric transformation upon heating and cooling. Attempts to study the structural changes associated with the valence-tautomeric transformation by single-crystal X-ray diffraction failed because of the crystal destruction taking place upon cooling from 220 K. The powder X-ray diffraction pattern indicated an essential change of the unit cell upon cooling from 240 K.

18.
Inorg Chem ; 56(5): 2426-2431, 2017 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-28212027

RESUMO

A new bis(3,6-di-tert-butyl-catecholato)manganese complex with two 4-NIT-Py ligands was synthesized and characterized [4-NIT-Py = pyridine substituted at position 4 with nitronyl-nitroxide radical, 2-(pyridin-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl]. X-ray diffraction indicated an octahedral environment of the manganese atom with a trans arrangement of ligands. Bonds lengths in the inner coordination core of the metal and in the chelate cycles that are representative of the charge distribution between the metal and ligands displayed a Mn(IV)(Cat2-)2 charge distribution. Variable-temperature magnetic susceptibility measurements detected intramolecular ferromagnetic coupling between the Mn(IV) S = 3/2 spins and spins of nitronyl-nitroxyls and intermolecular ferromagnetic interactions of spins of adjacent nitronyl-nitroxide fragments in a chain of molecules at low temperatures. The last phenomenon is revealed by short contacts between nitronyl-nitroxide radicals of adjacent complex molecules.

19.
Biochim Biophys Acta Gen Subj ; 1861(6): 1530-1544, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28130158

RESUMO

BACKGROUND: Theranostics, a fusion of two key parts of modern medicine - diagnostics and therapy of the organism's disorders, promises to bring the efficacy of medical treatment to a fundamentally new level and to become the basis of personalized medicine. Extrapolating today's progress in the field of smart materials to the long-run prospect, we can imagine future intelligent agents capable of performing complex analysis of different physiological factors inside the living organism and implementing a built-in program thereby triggering a series of therapeutic actions. These agents, by analogy with their macroscopic counterparts, can be called nanorobots. It is quite obscure what these devices are going to look like but they will be more or less based on today's achievements in nanobiotechnology. SCOPE OF REVIEW: The present Review is an attempt to systematize highly diverse nanomaterials, which may potentially serve as modules for theranostic nanorobotics, e.g., nanomotors, sensing units, and payload carriers. MAJOR CONCLUSIONS: Biocomputing-based sensing, externally actuated or chemically "fueled" autonomous movement, swarm inter-agent communication behavior are just a few inspiring examples that nanobiotechnology can offer today for construction of truly intelligent drug delivery systems. GENERAL SIGNIFICANCE: The progress of smart nanomaterials toward fully autonomous drug delivery nanorobots is an exciting prospect for disease treatment. Synergistic combination of the available approaches and their further development may produce intelligent drugs of unmatched functionality.


Assuntos
Técnicas Biossensoriais/instrumentação , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/instrumentação , Nanoestruturas/química , Preparações Farmacêuticas/química , Nanomedicina Teranóstica/instrumentação , Animais , Portadores de Fármacos/classificação , Composição de Medicamentos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Nanoestruturas/classificação , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/classificação , Terminologia como Assunto , Nanomedicina Teranóstica/métodos
20.
J Tissue Eng Regen Med ; 11(3): 778-786, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-25524377

RESUMO

Basic molecular mechanisms, associated with the main cell population of the dermis - fibroblasts - are the basis of skin aging. The number of functionally active fibroblasts in the skin and their biosynthetic activity decreases with age, thus enhancement of their cell density with synthetically active cells is accepted as a one of the most effective methods. The objective of the present study was to evaluate the safety and effectiveness of intradermal administration of autologous dermal fibroblasts in a year after treatment of 17 patients, aged 45-65 years. Results obtained with modern instrumental skin diagnostic methods (vacuum cutometry, optical profilometry, VISIA photometric analysis, etc.) demonstrate the safety and clinical effectiveness of dermal autofibroblast therapy: after transplantation, cultured autofibroblasts keep their biosynthetic activity and produce extracellular matrix for at least 12 months. As a result, remodelling of the dermis microstructures is observed, accompanied by a progressive increase of collagen content and thickness of the dermis (up to 62.5 ±6.7% in 12 months). This is clinically expressed by increase of skin elasticity (24.0 ±4.3% in periorbital area) and thickness of the skin, and by decrease in the number and depth of wrinkles (46 ±7% by the end of observation period). Copyright © 2014 John Wiley & Sons, Ltd.


Assuntos
Derme/citologia , Fibroblastos/citologia , Fibroblastos/transplante , Idoso , Ensaio de Unidades Formadoras de Colônias , Elasticidade , Face , Feminino , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Envelhecimento da Pele/fisiologia , Transplante Autólogo
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