RESUMEN
Integrin beta-3 is a cell adhesion molecule that mediate cell-to-cell and cell-to-extracellular matrix communication. The major goal of this study was to explore melanoma cells (B16F10) based upon specific direct targeting of the ß3 subunit (CD61) in the integrin αvß3 receptor using carbon-encapsulated iron nanoparticles decorated with monoclonal antibodies (Fe@C-CONH-anti-CD61 and Fe@C-(CH2)2-CONH-anti-CD61). Both melanoma cells treated with nanoparticles as well as C57BL/6 mice bearing syngeneic B16-F10 tumors intravenously injected with nanoparticles were tested in preclinical MRI studies. The as-synthesized carbon-encapsulated iron nanoparticles functionalized with CD61 monoclonal antibodies have been successfully used as a novel targeted contrast agent for MRI-based tracking melanoma cells expressing the ß3 subunit of the integrin αvß3 receptor.
Asunto(s)
Antineoplásicos , Melanoma , Nanopartículas , Animales , Ratones , Melanoma/diagnóstico por imagen , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Integrina alfaVbeta3/metabolismo , Anticuerpos Monoclonales/farmacología , Hierro/farmacología , Ratones Endogámicos C57BL , Imagen por Resonancia Magnética , Adhesión Celular , Antineoplásicos/farmacología , Carbono/uso terapéuticoRESUMEN
The rapid progress of nanotechnology has led to use different nanomaterials for biomedical applications. Among them, graphene-encapsulated magnetic nanoparticles (GEMNS) are recognized as next generation carbon nanomaterials in translation cancer research. In this study, we utilized green fluorescence protein (GFP) expression plasmid DNA (pDNA) and GEMNS decorated with branched polyethyleneimine (PEI) to yield a novel transporter (GEMNS-PEI/pDNA) for gene delivery into melanoma cells (B16F10). The efficiency of transfection was examined using PCR and confocal microscopy. The studies show that the as-designed GEMNS-PEI construct is successfully used to transfect the melanoma cells with pDNA and it should be considered as a potent non-viral vector for introducing naked nucleic acids into eucaryotic cells.
Asunto(s)
Grafito , Melanoma , Nanopartículas , Humanos , Hierro , Técnicas de Transferencia de Gen , Transfección , Plásmidos , ADN/metabolismo , PolietileneiminaRESUMEN
2D graphene the most investigated structures from nanocarbon family studied in the last three decades. It is projected as an excellent material useful for quantum computing, artificial intelligence, and next generation advanced technologies. Graphene exists in several forms and its extraordinary thermal, mechanical, and electronic properties, principally depend on the kind of perfection of the hexagonal atomic lattice. Defects are always considered as undesired components but certain defects in graphene could be an asset for electrochemistry and quantum electronics due to the engineered electronclouds and quantum tunnelling. The authors carefully discuss the Stone-Wales imperfections in graphene and its derivatives comprehensively. A specific emphasis is focused on the experimental and theoretical aspects of the Stone-Wales defects in graphene with respect to structure-property relationships. The corroboration of extrinsic defects like external atomic doping, functionalization, edge distortion in the graphene consisting of Stone-Wales imperfections, which are very significant in designing graphene-based electronic devices, are summarized.
RESUMEN
The synthesis of graphitic carbon nitride (g-C3N4) doped with s-block metals is described. The materials were synthesized via thermal polycondensation of cyanamide and the appropriate metal chloride. The inclusion of the metal precursor strongly influenced the surface chemistry features as well as the textural, morphological, and structural properties of the g-C3N4. The doping of g-C3N4with s-block metals markedly enhanced its adsorption performance, which was studied during the removal of two model solutes (methyl blue and copper ions) from aqueous solutions. The maximum adsorption capacity for the organic dye was increased by 680 times after the doping process. The uptake of copper(II) increased ca. 30 times for the doped g-C3N4. The improvement of the adsorption performance is discussed in terms of the surface chemistry and textural features.
RESUMEN
ABSTRACT: The synthesis of a novel supramolecular system comprising of branched polyethylenimine and cyclodextrin, is presented. The synthesis route is based on the self-assembly phenomena with the inclusion of solvent molecules. The systems are formed by a hydrogen-bonding network and host-guest type interactions between the building blocks. It was found that the native cyclodextrin and polyethylenimine are able to form stable systems when the reaction medium constitutes a polar solvent forming host-guest type complexes with cyclodextrin. A special consideration was paid on the detailed spectroscopic analyses of the obtained water-soluble constructs, including ROESY and diffusion-ordered (DOSY) NMR spectroscopy studies. The versatility and significance of DOSY technique for the analysis of the cyclodextrin complexes and its non-covalent systems with branched polymers, were presented. It was also found that the guest molecules that were incorporated in the complexes exhibited enhanced thermal stability. The morphological details in the solid state were obtained by scanning electron microscope.
RESUMEN
Carbon-encapsulated iron nanoparticles (CEINs) have been considered as attractive candidates for several biomedical applications. In the present study, we synthesized CEINs (the mean diameter 40-80 nm) using a carbon arc route, and the as-synthesized CEINs were characterized (scanning and transmission electron microscopy, dynamic light scattering, turbidimetry, Zeta potential) and further tested as raw and purified nanomaterials containing the carbon surface modified with acidic groups. For cytotoxicity evaluation, we applied a battery of different methods (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase, calcein AM/propidium iodide, annexin V/propidium iodide, JC-1, cell cycle assay, Zeta potential, TEM and inductively coupled plasma mass spectrometry) to address the strategic cytotoxic endpoints of Lewis lung carcinoma cells due to CEIN (0.0001-100 µg ml(-1) ) exposures in vitro. Our studies evidence that incubation of Lewis lung carcinoma cells with CEINs is accompanied in substantial changes of zeta potential in cells and these effects may result in different internalization profiles. The results show that CEINs increased the mitochondrial and cell membrane cytotoxicity; however, the raw CEIN material (Fe@C/Fe) produced higher toxicities than the rest of the CEINs studied to data. The study showed that non-modified CEINs (Fe@C/Fe and Fe@C) elevated some pro-apoptotic events to a greater extent compared to that of the surface-modified CEINs (Fe@C-COOH and Fe@C-(CH2 )2 COOH). They also diminished the mitochondrial membrane potentials. In contrast to non-modified CEINs, the surface-functionalized nanoparticles caused the concentration- and time-dependent arrest of the S phase in cells. Taken all together, our results shed new light on the rational design of CEINs, as their geometry, hydrodynamic and, in particular, surface characteristics are important features in selecting CEINs as future nanomaterials for nanomedicine applications.
Asunto(s)
Apoptosis/efectos de los fármacos , Carbono/toxicidad , Hierro/toxicidad , Nanopartículas del Metal/toxicidad , Animales , Carbono/química , Carcinoma Pulmonar de Lewis/patología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Citometría de Flujo , Hierro/química , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Nanopartículas del Metal/química , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Espectrofotometría Atómica , Propiedades de SuperficieRESUMEN
New materials are the backbone of their technology-driven modern civilization and at present carbon nanostructures are the leading candidates that have attracted huge research activities. Diamanes and diamanoids are the new nanoallotropes of sp3 hybridized carbon which can be fabricated by proper functionalization, substitution, and via Birch reduction under controlled pressure using graphitic system as a precursor. These nanoallotropes exhibit outstanding electrical, thermal, optical, vibrational, and mechanical properties, which can be an asset for new technologies, especially for quantum devices, photonics, and space technologies. Moreover, the features like wide bandgap, tunable thermal conductivity, excellent thermal insulation, etc. make diamanes and diamanoids ideal candidates for nano-electrical devices, nano-resonators, optical waveguides, and the next generation thermal management systems. In this review, diamanes and diamanoids are discussed in detail in terms of its historical prospect, method of synthesis, structural features, broad properties, and cutting-edge applications. Additionally, the prospects of diamanes and diamanoids for new applications are carefully discussed. This review aims to provide a critical update with important ideas for a new generation of quantum devices based on diamanes and diamanoids which are going to be an important topic in the future of carbon nanotechnology.
RESUMEN
Surface functionalized carbon-encapsulated iron nanoparticles (CEINs) were found to be a magnetic nanocatalyst for the efficient and highly selective synthesis of benzimidazoles. CEINs were covalently decorated with carboxyl or sulfonyl groups and their catalytic activity was examined. Carboxyl-modified CEINs were obtained via the radical or oxidative treatment, whilst the sulfonated CEINs were obtained using the one-step diazotization approach with sulfanilic acid and isoamyl nitrite. The content of surface acidic groups varied between the obtained materials and was found to be the highest for sulfonyl-modified CEINs. CEINs functionalized with sulfonyl groups were the most efficient and the most selective nanocatalyst for the synthesis of benzimidazoles. Various benzimidazoles were obtained in very high yields (92.5-97.0%). Both metallocene, aliphatic, heterocyclic and aromatic aldehydes substituted with different functional groups were subjected to the synthesis process. The reaction proceeded in a short time, which varied from 25 min to 65 min depending on the aldehyde used. Additionally, the mechanism of the studied catalytic condensation by applying sulfonated CEINs as the catalyst was discussed. Importantly, the developed magnetic nanocatalysts could be easily separated from the reaction mixture using a permanent magnet. The nanocatalysts can be used up to six reaction cycles without any significant loss of their catalytic activity. This work opens up new ways for very efficient and simple synthesis of benzimidazoles - an important class of organic compounds for various biomedical applications.
RESUMEN
The way of immobilization of the monoclonal antibody (type IgG) on the electrode surface has a significant effect on the amount of the immobilized protein and in consequence on current signal of protein. Herein, we demonstrate that the application of appropriately functionalized phenyl film allowed us to control the orientation of the antibody (Ab) molecules on the electrode surface. The influence of Ab orientation on the efficiency of antigen-antibody interaction was tested with an example blood plasma protein (ferritin; Ft). To control the orientation of Ab molecules the phenyl films containing -COOH or -NH2 groups were applied. Contrary to aminoethylophenyl layer, the carboxyphenyl film guaranteed the shortest distance between the redox center of the protein and the electrode surface. Additionally, the application of an external magnetic field together with magnetic nanoparticles allowed achieving the best orientation to observe well-defined ferritin current signals. The proposed method of ferritin detection can be successfully used in the concentration range of Ft between 0.1 and 30⯵gâ¯dL-1. The detection limit for a carboxyphenyl film was estimated as 0.40⯱â¯0.04 and 0.13⯱â¯0.04⯵gâ¯dL-1 for impedance and voltammetric measurements, respectively. In turn, for an aminoethylophenyl film the detection limit was 0.03⯱â¯0.002 (electrochemical impedance spectroscopy; EIS) and 0.02⯱â¯0.002⯵gâ¯dL-1 (differential pulse voltammetry, DPV). The interday precision (reproducibility) was calculated (4.10 ÷ 9.10% RSD) together with the intraday precision / repeatability (3.20 ÷ 8.0% RSD) for the studied samples. The functionality of the sensor has been tested on rat blood samples. Based on the performed investigations it can be stated that the developed sensor was characterized by high selectivity and good sensitivity.
Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas/métodos , Ferritinas/aislamiento & purificación , Nanopartículas del Metal/química , Animales , Anticuerpos/química , Espectroscopía Dieléctrica , Ferritinas/química , Oro/química , Grafito/química , Límite de Detección , RatasRESUMEN
The mechanochemical covalent functionalization of carbon-encapsulated iron nanoparticles (CEINs) is reported. Unprotected sugars (mannose, galactose, ß-cyclodextrin) and amino sugars (glucosamine and chitosan) were successfully conjugated to the surface of CEINs. The developed grinding-induced methods employ (i) the 1,3-dipolar cycloadditions of nitrile oxides or azomethine ylides and (ii) amidation-type reactions with the inclusion of carboxyl-functionalized CEINs and amino sugars. All the developed mechanochemical processes are fast (reaction time 10 min) and result in high degrees of coverage (7.3-31.5 wt%). The presented functionalization routes also constitute easy to perform and environmentally improved protocols. Moreover, the use of toxic organic solvents is not required. A comprehensive study on the colloidal stability of the sugar-functionalized CEINs is also included in this work. The results of the turbidimetric analyses reveal that both grinding-induced formation of amide bonds and the cycloadditions of sugar moieties to the surface of CEINs result in the significant improvement of their colloidal stability. The highest stability of the aqueous dispersion was found for CEINs functionalized with ß-cyclodextrin. The comparative studies between the classical wet approach and the grinding-induced functionalization of CEINs show that the herein developed environmentally improved method increases the colloidal stability three times. The crucial role of the mechanochemical approach in the covalent functionalization of CEINs and the improvement of their colloidal stability is discussed in this work.
RESUMEN
The nanoparticles comprising of iron core and carbon shell were decorated with ferrocene derivatives: ferrocenecarboxaldehyde (Fc-1) and ferrocenecarboxaldehyde oxime (Fc-2). A microdrop of suspension of the nanoconjugate was placed on a glassy-carbon electrode to prepare the recognition/sensing layer. Drying and purification of the sensing layer resulted in a well-defined and stable square-wave voltammogram of the ferrocene moiety. The height of the voltammetric peak increased in the presence of ceruloplasmin. That increase was linearly dependent on the logarithmic concentration of ceruloplasmin in blood. The applied external magnetic field was a factor which yielded better sensitivity and repeatability of the sensor response. The linearity of sensor response was found to be between 0.001 and 10µgdL-1 and 0.05-10µgdL-1 for both nanoconjugates: Fe@C-Fc-1 and Fe@C-Fc-2, in the presence and absence of the magnet, respectively. The obtained detection limit (LOD) for Fe@C-Fc-1 was found to be 0.60 and 0.10µgdL-1 in the absence and presence of magnetic field, respectively, whilst for Fe@C-Fc-2 was 0.4 and 0.07µgdL-1 in the absence and presence of a magnet, respectively. The proposed method is selective because the presence of common antioxidants in blood did not interfere significantly with the determination of the concentration of ceruloplasmin.
Asunto(s)
Técnicas Biosensibles/métodos , Ceruloplasmina/aislamiento & purificación , Compuestos Ferrosos/química , Metalocenos/química , Nanoconjugados/química , Carbono/química , Humanos , Hierro , Límite de Detección , Nanopartículas del Metal/química , Oximas/químicaRESUMEN
Nanomaterials and nanoparticles are regarded as promising candidates for various biomedical applications due to their unique physicochemical properties. In this study, three types of carbon-encapsulated iron nanoparticles (CEINs) were synthesized and their impact on cellular changes was investigated by atomic force microscopy (AFM). The AFM experiment was additionally compared with conventional methods, such as colorimetric assay and other microscopic techniques. A significant difference of reduced Young's modulus of the cells was revealed, even at low concentration of nanoparticles in the culture medium. The AFM measurement proved to be a useful tool not only for visualization, but also for identification of local cellular changes at the nanoscale after exposure to carbon-encapsulated iron nanoparticles.
Asunto(s)
Módulo de Elasticidad/efectos de los fármacos , Células Madre Mesenquimatosas/fisiología , Nanopartículas del Metal/química , Microscopía de Fuerza Atómica/métodos , Citoesqueleto de Actina/metabolismo , Humanos , HierroRESUMEN
Carbon encapsulated magnetic nanoparticles may find many prospective biomedical applications, e.g., in drug and gene delivery systems, disease detection, cancer therapy, rapid toxic cleaning, biochemical sensing, and magnetic resonance imaging. Each of these applications hinges on the relationship between magnetic fields and biological systems. Herein we present the results on the thermal stability of carbon encapsulated magnetic nanoparticles. The products were synthesized by using induction radio frequency (RF) thermal plasma. Phase composition and morphology were studied by powder X-ray diffraction and HRTEM, respectively. Thermal stability was investigated by thermogravimetry and differential thermal analyses. Carbon nanostructures were thermally stable up to 500 K.
Asunto(s)
Materiales Biocompatibles/química , Carbono/química , Magnetismo , Nanopartículas/química , Temperatura , Materiales Biocompatibles/síntesis química , Cápsulas/química , Estabilidad de Medicamentos , Microscopía Electrónica de Transmisión/métodos , Tamaño de la Partícula , Propiedades de Superficie , Termogravimetría , Difracción de Rayos XRESUMEN
In this Article, we describe a carbon nanotube formation model in which sp2 carbon hemispheres form the embryonic caps from which a nanotube can grow. This requirement leads to a single wall carbon nanotube formation window concomitant with our systematic experimental findings, which show upper and lower diameter limits. Further, the successful formation of a nucleation cap (hemisphere) is governed by catalyst particle volume to surface area considerations. Single wall carbon nanotubes are only obtained when both the nanotube formation window and the precipitating catalyst size distribution cross over. The extent to which these two windows overlap establishes the mean diameter and diameter distribution of the obtained single wall carbon nanotubes.
RESUMEN
The Prato reaction was applied for the covalent introduction of a variety of organic moieties onto carbon-encapsulated iron nanoparticles. The developed method is versatile and employs a broad range of commercially available reactants, including both aromatic and aliphatic aldehydes. The reported functionalization route provides high functionalization yields (ca. 12-21 wt%).
RESUMEN
This study presents for the first time the direct amination of graphene-encapsulated iron nanoparticles (GEINs) with polyethylenimine (PEI) via radical-type reaction. This work describes the first example of a direct addition of N-centered radical species onto the graphene layer. The pristine PEI and the PEI attached to GEINs have also been derivatized to introduce sulfhydryl functionalities. The proposed two-step protocol constitutes a novel, versatile and low cost method for the synthesis of polymer derivatives decorated with SH moieties. The derivatives of pristine polyethylenimine were analyzed by means of spectroscopic methods (NMR and IR), while the obtained carbon materials were studied by thermogravimetry, infrared spectroscopy, dynamic light scattering, and transmission electron microscopy. Finally, the concomitant part of this work focused on the bioconjugation type reactions of various biocompounds, including bovine gamma-globulins and human polyclonal antibodies of class IgG, with the as-obtained sulfhydrylated GEINs-PEI nanoplatform. The presence of immobilized molecules was confirmed by thermogravimetry, protein and fluorescence assays as well as confocal microscopy images.
RESUMEN
The control of the interactions of proteins with the support matrix plays a key role in medicine, drug delivery systems and diagnostics. Herein, we report that covalent anchoring of human transferrin to carbon-coated iron magnetic nanoparticles functionalized with carboxylic groups (Fe@C-COOH Nps) in the presence of magnetic field results in its conformational integrity and electroactivity. We have found that, the direct contact of human transferrin with Fe@C-COOH Nps does not lead to release of iron and in consequence to the irreversible conformational changes of the protein. Moreover, the examination of the direct electron transfer between Tf molecules from the conjugate and the electrode surface was possible. The quartz crystal microbalance with dissipation (QCM-D)- and thermogravimetric data (TGA) showed that under such conditions, in addition to a monolayer, an adlayer of the protein can be formed on Fe@C-COOH Nps at constant pH. STATEMENT OF SIGNIFICANCE: To our best knowledge this is the first paper that reports on covalent anchoring of human transferrin (Tf) to carbon-coated iron magnetic nanoparticles functionalized with carboxylic groups (Fe@C-COOH Nps) in the presence of magnetic field, which results in its conformational integrity and electroactivity. We showed that it is possible to attach, without changing pH, more than one single layer of transferrin to the Fe@C-COOH Nps. This is a very rare phenomenon in the case of proteins. We proved, using various experimental techniques, that the proposed methodology does not lead to release of iron from Tf molecules, what was the major problem so far. We believe that this finding opens new possibilities in targeting drug delivery systems and medical diagnostics.
Asunto(s)
Carbono/química , Hierro/química , Campos Magnéticos , Nanopartículas/química , Transferrina/química , Dicroismo Circular , Técnicas Electroquímicas , Electrodos , Oro/química , Humanos , Conformación Proteica , Tecnicas de Microbalanza del Cristal de Cuarzo , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , TermogravimetríaRESUMEN
Carbon-encapsulated iron nanoparticles (CEINs) qualified as metal-inorganic hybrid nanomaterials offer a potential scope for an increasing number of biomedical applications. In this study, we have focused on the investigation of cellular fate and resulting cytotoxic effects of CEINs synthesized using a carbon arc route and studied in murine endothelial (HECa-10) cells. The CEIN samples were characterized as pristine (the mean diameter between 47 and 56nm) and hydrodynamic (the mean diameter between 270 and 460nm) forms and tested using a battery of methods to determine the cell internalization extent and cytotoxicity effects upon to the exposures (0.0001-100µg/ml) in HECa-10 cells. Our studies evidenced that the incubation with CEINs for 24h is accompanied with substantial changes of Zeta potential in cells which can be considered as a key factor for affecting the membrane transport, cellular distribution and cytotoxicity of these nanoparticles. The results demonstrate that CEINs have entered the endothelial cell through the endocytic pathway rather than by passive diffusion and they were mainly loaded as agglomerates on the cell membrane and throughout the cytoplasm, mitochondria and nucleus. The studies show that CEINs induce the mitochondrial and cell membrane cytotoxicities in a dose-dependent manner resulting from the internal dosages due to CEIN agglomerates. Our results highlight the importance of the physicochemical characterization of CEINs in studying the magnetic nanoparticle-endothelial cell interactions because the CEIN mass agglomerates can sediment more or less rapidly in culture models.
Asunto(s)
Carbono/toxicidad , Células Endoteliales/efectos de los fármacos , Hierro/toxicidad , Nanopartículas del Metal/toxicidad , Animales , Carbono/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Endocitosis , Células Endoteliales/ultraestructura , Hierro/química , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Ratones , Microscopía Electrónica de Rastreo , Microscopía Electrónica de TransmisiónRESUMEN
1-D nanostructures of cubic phase silicon carbide (beta-SiC) were efficiently produced by combustion synthesis of mixtures containing Si-containing compounds and halocarbons in a calorimetric bomb. The influence of the operating parameters on 1-D SiC formation yield was studied. The heat release, the heating rate, and the chamber pressure increase were monitored during the process. The composition and structural features of the products were characterized by elemental analysis, X-ray diffraction, differential thermal analysis/ thermogravimetric technique, Raman spectroscopy, scanning and transmission electron microscopy, and energy-dispersive X-ray spectrometry. This self-induced growth process can produce SiC nanofibers and nanotubes ca. 20-100 nm in diameter with the aspect ratio higher than 1000. Bulk scale Raman studies showed the product to be comprised of mostly cubic polytype of SiC and that finite size effects are present. We believe that the nucleation mechanism involving radical gaseous species is responsible for 1-D nanostructures growth. The present study has enlarged the family of nanofibers and nanotubes available and offers a possible, new general route to 1-D crystalline materials.
Asunto(s)
Compuestos Inorgánicos de Carbono/química , Compuestos Inorgánicos de Carbono/síntesis química , Nanoestructuras , Compuestos de Silicona/química , Compuestos de Silicona/síntesis química , Aire , Argón , Calorimetría , Helio , Cinética , Microscopía Electrónica de Rastreo , Modelos Moleculares , Conformación Molecular , Nanotecnología , OxígenoRESUMEN
An effective, fast, facile and direct electrochemical method of determination of hemoglobin (Hb) in blood sample without any sample preparation is described. The method is accomplished by using the ferromagnetic electrode modifier (carbon-encapsulated iron nanoparticles) and an external magnetic field. The successful voltammetric determination of hemoglobin is achieved in PBS buffer as well as in the whole blood sample. The obtained results show the excellent electroactivity of Hb. The measurements are of high sensitivity and good reproducibility. The detection limit is estimated to be 0.7 pM. The electrochemical determination data were compared with the gravimetric data obtained with a quartz crystal microbalance. The agreement between these results is very good. The changes of the electrode surface morphology before and after Hb detection are monitored by electron microscopy. The functionality of the electrochemical sensor is tested with human and rat blood samples. The concentration of hemoglobin in the blood samples determined by using voltammetric/gravimetric detection is in perfect agreement with the data obtained from typical clinical analysis.