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1.
Top Curr Chem (Cham) ; 378(1): 15, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31938922

RESUMO

Nowadays, biomaterials have become a crucial element in numerous biomedical, preclinical, and clinical applications. The use of nanoparticles entails a great potential in these fields mainly because of the high ratio of surface atoms that modify the physicochemical properties and increases the chemical reactivity. Among them, carbon nanotubes (CNTs) have emerged as a powerful tool to improve biomedical approaches in the management of numerous diseases. CNTs have an excellent ability to penetrate cell membranes, and the sp2 hybridization of all carbons enables their functionalization with almost every biomolecule or compound, allowing them to target cells and deliver drugs under the appropriate environmental stimuli. Besides, in the new promising field of artificial biomaterial generation, nanotubes are studied as the load in nanocomposite materials, improving their mechanical and electrical properties, or even for direct use as scaffolds in body tissue manufacturing. Nevertheless, despite their beneficial contributions, some major concerns need to be solved to boost the clinical development of CNTs, including poor solubility in water, low biodegradability and dispersivity, and toxicity problems associated with CNTs' interaction with biomolecules in tissues and organs, including the possible effects in the proteome and genome. This review performs a wide literature analysis to present the main and latest advances in the optimal design and characterization of carbon nanotubes with biomedical applications, and their capacities in different areas of preclinical research.


Assuntos
Nanomedicina/métodos , Nanotecnologia/métodos , Nanotubos de Carbono/análise , Animais , Humanos , Modelos Moleculares , Nanotubos de Carbono/toxicidade , Nanotubos de Carbono/ultraestrutura
2.
Int J Nanomedicine ; 14: 8433-8444, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749617

RESUMO

Aims: Different kinds of vitamins can be used as promising candidates to mitigate the structural changes of proteins and associated cytotoxicity stimulated by NPs. Therefore, the structural changes of α-syn molecules and their associated cytotoxicity in the presence of SWCNTs either alone or co-incubated with vitamin K1 were studied by spectroscopic, bioinformatical, and cellular assays. Methods: Intrinsic and ThT fluorescence, CD, and Congo red absorption spectroscopic approaches as well as TEM investigation, molecular docking, and molecular dynamics were used to explore the protective effect of vitamin K1 on the structural changes of α-syn induced by SWCNTs. The cytotoxicity of α-syn/SWCNTs co-incubated with vitamin K1 against SH-SY5Y cells was also carried out by MTT, LDH, and caspase-3 assays. Results: Fluorescence spectroscopy showed that vitamin K1 has a significant effect in reducing SWCNT-induced fluorescence quenching and aggregation of α- syn. CD, Congo red adsorption, and TEM investigations determined that co-incubation of α- syn with vitamin K1 inhibited the propensity of α-syn into the structural changes and amorphous aggregation in the presence of SWCNT. Docking studies determined the occupation of preferred docked site of SWCNT by vitamin K1 on α- syn conformation. A molecular dynamics study also showed that vitamin K1 reduced the structural changes of α- syn induced by SWCNT. Cellular data exhibited that the cytotoxicity of α- syn co-incubated with vitamin K1 in the presence of SWCNTs is less than the outcomes obtained in the absence of the vitamin K1. Conclusion: It may be concluded that vitamin K1 decreases the propensity of α- syn aggregation in the presence of SWCNTs and induction of cytotoxicity.


Assuntos
Nanotubos de Carbono/química , Vitamina K 1/farmacologia , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Adsorção , Benzotiazóis/metabolismo , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Vermelho Congo , Humanos , L-Lactato Desidrogenase/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Nanotubos de Carbono/ultraestrutura , Espectrometria de Fluorescência
3.
Int J Nanomedicine ; 14: 6645-6659, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686804

RESUMO

Introduction: It is well known that the grafted multiwalled carbon nanotubes (MWCNTs) have antibacterial activity and lower cytotoxicity. Moreover, pyrazole derivatives have a broad spectrum of biological activity due to their fertile template for many medicinal drugs. On view of these findings we report herein the hybridization between MWCNTs and some pyrazole derivatives as antibacterial agents. Materials and methods: Pyrazole and pyrazolone derivatives were grafted onto the surface of carboxylated MWCNTs via the reaction of carboxylated MWCNTs and the diazonium salts of pyrazoles and pyrazolones using mixed acid treatment. The insertion of the pyrazole and pyrazolone moieties was characterized by Fourier transform infrared (FTIR) spectroscopy, energy dispersion spectroscopy, transmission electron microscopy, X-ray diffraction and thermogravimetric (TGA). Results: The results indicate that pyrazole and pyrazolone moieties successfully attached on carboxylated MWCNTs surface. The neat pyrazole and pyrazolone derivatives and their corresponding carbon nanotubes were tested against Staphylococcus aureus, Bacillus subtilus, Escherichia coli, and Candida albicans bacteria, and Aspergillusniger fungi. The results showed that the grafted carbon nanotubes of pyrazole and pyrazolone derivatives have better antimicrobial activity than the neat pyrazole and pyrazolone derivatives. The molecular docking studies were performed on the most potent antimicrobial compounds to investigate the existence of the interactions between the most active inhibitors and Farnesyl pyrophosphate synthase (FPPS). Conclusion: The surface of the carboxylated MWCNTs was successfully grafted with some pyrazole derivatives. The antibacterial activity was investigated for the newly synthesized compounds and indicated that the grafted MWCNTs have good antibacterial activity toward some pathogenic types of bacteria.


Assuntos
Antibacterianos/farmacologia , Simulação de Acoplamento Molecular , Nanotubos de Carbono/química , Pirazóis/química , Pirazóis/farmacologia , Bactérias/efeitos dos fármacos , Domínio Catalítico , Fungos/efeitos dos fármacos , Ligantes , Testes de Sensibilidade Microbiana , Nanotubos de Carbono/ultraestrutura , Pirazóis/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
4.
Int J Nanomedicine ; 14: 8445-8467, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31754301

RESUMO

Purpose: Over the past 30 years, no consistent survival benefits have been recorded for anticancer agents of advanced hepatocellular carcinoma (HCC), except for the multikinase inhibitor sorafenib (Nexavar®), which clinically achieves only ~3 months overall survival benefit. This modest benefit is attributed to limited aqueous solubility, slow dissolution rate and, consequently, limited absorption from the gastrointestinal tract. Thus, novel formulation modalities are in demand to improve the bioavailability of the drug to attack HCC in a more efficient manner. In the current study, we aimed to design a novel sorafenib-loaded carbon nanotubes (CNTs) formula that is able to improve the therapeutic efficacy of carried cargo against HCC and subsequently investigate the antitumour activity of this formula. Materials and methods: Sorafenib was loaded on functionalized CNTs through physical adsorption, and an alginate-based method was subsequently applied to microcapsulate the drug-loaded CNTs (CNTs-SFN). The therapeutic efficacy of the new formula was estimated and compared to that of conventional sorafenib, both in vitro (against HepG2 cells) and in vivo (in a DENA-induced HCC rat model). Results: The in vitro MTT anti-proliferative assay revealed that the drug-loaded CNTs formula was at least two-fold more cytotoxic towards HepG2 cells than was sorafenib itself. Moreover, the in vivo animal experiments proved that our innovative formula was superior to conventional sorafenib at all assessed end points. Circulating AFP-L3% was significantly decreased in the CNTs-SFN-MCs-treated group (14.0%) in comparison to that of the DENA (40.3%) and sorafenib (38.8%) groups. This superiority was further confirmed by Western blot analysis and immunofluorescence assessment of some HCC-relevant biomarkers. Conclusion: Our results firmly suggest the distinctive cancer-suppressive nature of CNTs-SFN-MCs, both against HepG2 cells in vitro and in a DENA-induced HCC rat model in vivo, with a preferential superiority over conventional sorafenib.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Desenho de Drogas , Neoplasias Hepáticas/tratamento farmacológico , Nanotubos de Carbono/química , Sorafenibe/uso terapêutico , Animais , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/metabolismo , Peso Corporal/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Proliferação de Células/efeitos dos fármacos , Composição de Medicamentos , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Fígado/efeitos dos fármacos , Fígado/patologia , Neoplasias Hepáticas/patologia , Masculino , Nanotubos de Carbono/ultraestrutura , Niacinamida/farmacologia , Ratos Wistar , Sorafenibe/sangue , Sorafenibe/farmacocinética , Sorafenibe/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
5.
Int J Nanomedicine ; 14: 6465-6480, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31616140

RESUMO

Purpose: Multiwalled carbon nanotubes (MWCNTs) have been known to enter the circulatory system via the lungs from inhalation exposure; however, its carcinogenicity and subsequent accumulation in other organs have not been adequately reported in the literature. Moreover, the safety of MWCNTs as a biomaterial has remained a matter of debate, particularly when the material enters the circulatory system. To address these problems, we used carcinogenic rasH2 transgenic mice to intravenously administer highly dispersed MWCNTs and to evaluate their carcinogenicity and accumulation in the organs. Methods: Two types of MWCNTs (thin- and thick-MWCNTs) were intravenously administered at a high dose (approximately 0.7 mg per kg body weight) and low dose (approximately 0.07 mg per kg body weight). Results: MWCNTs showed pancreatic accumulation in 3.2% of mice administered with MWCNTs, but there was no accumulation in other organs. In addition, there was no significant difference in the incidence of tumor among the four MWCNTs-administered groups compared to the vehicle group without MWCNTs administration. Blood tests revealed elevated levels in mean red blood cell volume and mean red blood cell hemoglobin level for the MWCNTs-administered group, in addition to an increase in eotaxin. Conclusion: The present study demonstrated that the use of current technology to sufficiently disperse MWCNTs resulted in minimal organ accumulation with no evidence of carcinogenicity.


Assuntos
Carcinógenos/toxicidade , Nanotubos de Carbono/toxicidade , Administração Intravenosa , Animais , Peso Corporal , Carcinogênese/patologia , Citocinas/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Camundongos Transgênicos , Nanotubos de Carbono/ultraestrutura , Análise de Sobrevida , Distribuição Tecidual/efeitos dos fármacos
6.
Int J Nanomedicine ; 14: 7947-7962, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632010

RESUMO

Purpose: Hydroxyapatite (HA) is a biologically active ceramic which promotes bone growth, but it suffers from relatively weak mechanical properties. Multi-walled carbon nanotubes (MWCNTs) have high tensile strength and a degree of stiffness that can be used to strengthen HA; potentially improving the clinical utility of the bone implant. Methods: HA was precipitated by the wet precipitation method in the presence of pristine (p) or functionalised (f) MWCNTs, and polyvinyl alcohol (PVA) or hexadecyl trimethyl ammonium bromide (HTAB) as the surfactant. The resulting composites were characterised and the diametral tensile strength and compressive strength of the composites were measured. To determine the biocompatibility of the composites, human osteoblast cells (HOB) were proliferated in the presence of the composites for 7 days. Results: The study revealed that both the MWCNTs and surfactants play a crucial role in the nucleation and growth of the HA. Composites made with f-MWCNTs were found to have better dispersion and better interaction with the HA particles compared to composites with p-MWCNTs. The mechanical strength was improved in all the composites compared to pure HA composites. The biocompatibility study showed minimal LDH activity in the media confirming that the composites were biocompatible. Similarly, the ALP activity confirmed that the cells grown on the composites containing HTAB were comparable to the control whereas the composites containing PVA surfactant showed significantly reduced ALP activity. Conclusions: The study shows that the composites made of f-MWCNTs HTAB are stronger than pure HA composites and biocompatible making it a suitable material to study further.


Assuntos
Materiais Biocompatíveis/química , Osso e Ossos/fisiologia , Durapatita/química , Teste de Materiais , Nanocompostos/química , Nanotubos de Carbono/química , Próteses e Implantes , Fosfatase Alcalina/metabolismo , Forma Celular , Força Compressiva , Eletrólitos/química , Humanos , L-Lactato Desidrogenase/metabolismo , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Osteoblastos/citologia , Osteoblastos/enzimologia , Osteoblastos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Difração de Raios X
7.
Mater Sci Eng C Mater Biol Appl ; 104: 109935, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500057

RESUMO

The slow degradation of Fe severely restricts its application in bone repair although it possesses good biocompatibility and high mechanical properties. In this study, carbon nanotubes (CNTs) were introduced to accelerate Fe biodegradation: (I) CNTs acted as cathodes to induce galvanic corrosion owing to their differences in corrosion potential; (II) The large specific surface area of CNTs increased area ratios of cathode to anode; (III) The excellent electrical conductivity of CNTs allowed significant levels of electron transfer through the cathode in galvanic corrosion. Consequently, the degradation rate of Fe/CNTs composites greatly increased by 74% with the increase of CNTs (0.3-0.9 wt%). Further addition of CNTs would lead to corrosion holes and cracks due to localized corrosion. Besides, cell culture experiments showed that MG-63 cells could normally proliferate to maintain their population, indicating good cytocompatibility of Fe/CNTs composites. The results proved that the incorporation of CNTs into Fe was an effective approach to develop Fe-based bone implants with enhanced degradation rates.


Assuntos
Ferro/química , Nanotubos de Carbono/química , Biodegradação Ambiental , Linhagem Celular Tumoral , Sobrevivência Celular , Corrosão , Eletroquímica , Dureza , Humanos , Nanotubos de Carbono/ultraestrutura , Tamanho da Partícula , Difração de Raios X
8.
Molecules ; 24(17)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480573

RESUMO

A novel tweakable nanocomposite was prepared by spark plasma sintering followed by systematic oxidation of carbon nanotube (CNT) molecules to produce alumina/carbon nanotube nanocomposites with surface porosities. The mechanical properties (flexural strength and fracture toughness), surface area, and electrical conductivities were characterized and compared. The nanocomposites were extensively analyzed by field emission scanning electron microscopy (FE-SEM) for 2D qualitative surface morphological analysis. Adding CNTs in ceramic matrices and then systematically oxidizing them, without substantial reduction in densification, induces significant capability to achieve desirable/application oriented balance between mechanical, electrical, and catalytic properties of these ceramic nanocomposites. This novel strategy, upon further development, opens new level of opportunities for real-world/industrial applications of these relatively novel engineering materials.


Assuntos
Cerâmica/química , Nanocompostos/química , Nanotubos de Carbono/química , Óxido de Alumínio/química , Condutividade Elétrica , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura
9.
J Chromatogr A ; 1605: 460369, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31402105

RESUMO

Magnetic carbonized polyaniline nanotube composite (Fe3O4@c-PANI) was synthesized via a self-assemble approach for the extraction and determination of three xanthene colorants including erythrosine B (EB), phloxine B (PB) and rhodamine B (RB). The scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction were adopted to confirm the successful synthesis of Fe3O4@c-PANI. When Fe3O4@c-PANI was applied for extracting three xanthene colorants, satisfactory extraction recoveries ranging from 89.48% to 94.15% were obtained with the relative standard deviation value of 1.09%-4.01%. Compared with Fe3O4, c-PANI and commercial adsorbents, Fe3O4@c-PANI achieved better retraction recovery for three colorants. Furthermore, adsorption kinetics and isotherms studies were analyzed to prove the adsorption mechanism of anionic and cationic colorants on Fe3O4@c-PANI. The graphite layers and pyrrole groups of the as-prepared composite can provide hydrophobic, π-π and hydrogen bonding interaction with xanthene colorants. Fe3O4 nanoparticles played dual-functional roles contributing to the separation and adsorption. Coupled with high performance liquid chromatography, the established magnetic solid phase extraction method was used for the analysis of beverage and fish samples.


Assuntos
Compostos de Anilina/química , Bebidas/análise , Corantes/análise , Fenômenos Magnéticos , Nanotubos de Carbono/química , Xantenos/isolamento & purificação , Peixe-Zebra/metabolismo , Adsorção , Animais , Cromatografia Líquida de Alta Pressão , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Cinética , Nanotubos de Carbono/ultraestrutura , Alimentos Marinhos/análise , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Termogravimetria , Fatores de Tempo
10.
Biosens Bioelectron ; 142: 111566, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31404879

RESUMO

Cell free diagnosis of cancer is one of the crucial fields in new generation of medical technology. In this regard, cancer detection based on coastal fluids secreted from the tissues (named as secretome) has attracted a lot of attention. Lipids are important macromolecules could be found with much higher concentrations in secretome of cancer tissues vs. normal ones. On the other hand, lipids are the main dielectric components of the secretome with respect to proteins and ions. Here for the first time we introduced an electrochemical lipidomics based on electrical impedance spectroscopy (EIS) of the secretomes to detect the cancerous samples due to the lipidic content of their secretions. The EIS sensor was fabricated by multiwall carbon nanotube (MWCNT) arrays as conductive and super hydrophobic materials to have great interactive surface with the lipidic content of the solution. Results of the tests on the secretions of more than 100 human biopsied breast tissues showed the promising match between the charge transfer resistance (RCT) of samples' secretions and pathological states of the tissues with meaningful boundary (up to 8 kΩ for normal and more than 13 kΩ for cancer samples). Mass spectroscopic analyses confirmed the higher content of lipids in cancer secretomes. Electrical lipidomics of the secretome shed new lights in cell free cancer diagnosis and could be applied as a complementary clinical approach in all of biopsy based diagnoses in future.


Assuntos
Espectroscopia Dielétrica/instrumentação , Metabolismo dos Lipídeos , Nanotubos de Carbono/química , Neoplasias/metabolismo , Microambiente Tumoral , Linhagem Celular Tumoral , Desenho de Equipamento , Humanos , Nanotubos de Carbono/ultraestrutura , Neoplasias/diagnóstico
11.
Molecules ; 24(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443345

RESUMO

A hybrid nanocomposite consisting of hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) and cube mesoporous carbon (CMK-8) was applied in this study to construct an MWCNT-OH/CMK-8/gold electrode (GE) electrochemical sensor and simultaneously perform the electro-reduction of olaquindox (OLA) and carbadox (CBX). The respective peak currents of CBX and OLA on the modified electrode increased by 720- and 595-fold relative to the peak current of GE. The performances of the modified electrode were investigated with electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Then, the modified electrodes were used for the individual and simultaneous determination of OLA and CBX. The fabricated sensor demonstrated a linear response at 0.2-500 nmol/L in optimum experimental conditions, and the detection limits were 104.1 and 62.9 pmol/L for the simultaneous determination of OLA and CBX, respectively. As for individual determination, wide linear relationships were obtained for the detected OLA with levels of 0.05-500 nmol/L with LOD of 20.7 pmol/L and the detected CBX with levels of 0.10-500 nmol/L with LOD of 50.2 pmol/L. The fabricated sensor was successfully used in the independent and simultaneous determination of OLA and CBX in spiked pork samples.


Assuntos
Carbadox/análise , Técnicas Eletroquímicas , Membranas Artificiais , Nanocompostos , Nanotubos de Carbono , Quinoxalinas/análise , Eletrodos , Ouro , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Análise Espectral
12.
J Chromatogr A ; 1602: 168-177, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31303311

RESUMO

In this work, we presented the preparation of magnetic carbon nanotubes (MCNTs) functionalized with molecularly imprinted polymers (MIPs) for effective removal of aristolochic acid I (AAI) in traditional Chinese medicine (TCM). MCNTs@AAI-MIPs was obtained via a facile and environmental friendly sol-gel process. Firstly, MCNTs were synthesized by a solvothermal method. Then, the template molecules were self-assembled with the functional monomer phenyltrimethoxysilane (PTMOS) in the presence of ethanol and water. Finally, AAI-MIPs film was coated on the MCNTs to obtain product MCNTs@AAI-MIPs using tetraethyl-orthosilicate (TEOS) as cross-linker. The morphology and structure of prepared MIPs were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen gas adsorption and vibrating sample magnetometer (VSM). The adsorption properties were demonstrated by kinetic, isothermal and selective adsorption experiments. The results showed that the imprinted nanocomposites exhibited fast separation rate (10 s), high adsorption capacity (18.54 µg∙mg-1), short kinetic equilibrium time (15 min), and good selectivity to template molecule with imprinting factor (IF) of 3.17. A regression equation (y=57294x-4734.1) with good linearity was obtained in the concentration range of 0.1-200 µg∙mg-1 for AAI with a correlation coefficient (R2) of 0.9998. The limit of detection (LOD, S/N=3) was 0.034 µg∙mg-1. Moreover, high recoveries ranged from 80% to 110% (RSD=3.27%-8.16%) were received in spiked TCM samples. The results suggested that the proposed MCNTs@AAI-MIPs could efficiently and specifically capture AAI from an actual complex TCM samples.


Assuntos
Ácidos Aristolóquicos/isolamento & purificação , Magnetismo , Impressão Molecular/métodos , Nanotubos de Carbono/química , Polímeros/química , Adsorção , Cinética , Nanotubos de Carbono/ultraestrutura , Nitrogênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Difração de Raios X
13.
Int J Pharm ; 568: 118513, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301462

RESUMO

The fabrication of electrospun composite nanofiber mats used as drug delivery systems with controlled release property is of general interest in biomaterial sciences. The aim of this study was to investigate the effect of MWCNTs on the release profile of the hydrophilic drug. For this aim, tetracycline hydrochloride (TCH) loaded poly (lactic acid) (PLA)/polyvinylpyrrolidone (PVP)/TCH-multiwall carbon nanotubes (MWCNTs) composite fibrous mats were fabricated by electrospinning process, and the drug release profile, release kinetics and cytotoxicity were evaluated to determine the potential for utilization as drug delivery systems. Furthermore, the morphological and physicochemical properties of the composite PLA/PVP/TCH-MWCNTs fibrous mats were characterized. The results demonstrated that TCH and MWCNTs were successfully loaded into the PLA/PVP biopolymeric matrix and the addition of TCH or MWCNTs did not alter the uniform and beadless fibrous structure of the PLA/PVP fibers, resulting in increased Young's modulus and maintained the fibrous structure of the composite mats. Moreover, MWCNTs loaded electrospun mats showed much more controlled drug release manner, increased significantly the drug encapsulation efficiency and reduced the burst release of TCH. In vitro cytotoxicity assay showed that the PLA/PVP/TCH-MWCNTs composite mats did not have a toxic effect on the human umbilical vein endothelial cells (HUVECs). With the improved physicochemical and mechanical properties, controlled drug release-profile and cytocompatibility, the fabricated composite nanofiber mats may be used as therapeutic materials for the biomedical applications as drug delivery systems.


Assuntos
Antibacterianos/química , Nanotubos de Carbono/química , Tetraciclina/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Varredura , Nanotubos de Carbono/ultraestrutura , Poliésteres/química , Povidona/química
14.
Biosens Bioelectron ; 142: 111483, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279173

RESUMO

CuCo2O4 nanoparticles modified with nitrogen doped carbon nanotubes (CuCo2O4/N-CNTs) have high specific surface area and good electrical conductivity. Herein, a novel electrochemical sensor based on CuCo2O4/N-CNTs loaded molecularly imprinted polymer (MIP) modified glassy carbon electrode (GCE) is proposed for rapid and ultrasensitive detection of metronidazole (MNZ). The composite of CuCo2O4/N-CNTs with MIP significantly enhances the electrical signal. The electrochemical polymerization was performed with MNZ as template and aniline as functional monomer by cyclic voltammetry (CV), and differential pulse voltammetry (DPV) was used to detect MNZ. Factors that affect sensor response were optimized. Under the optimal experimental conditions, the DPV current response shows two linearity ranges for MNZ in the range of 0.005-0.1 µM and 0.1-100 µM with very low limit of detection (LOD) of 0.48 nM (S/N = 3). This electrochemical sensing system has high sensitivity, selectivity, excellent reproducibility, repeatability and stability. The recovery (95.9%-100.9%) and reasonable relative standard deviation (RSD) (3.2%-4.8%) for determination of real samples indicate the practicality of the sensing system. This sensing system has high potential for rapid determination of MNZ in samples such as metronidazole tablets, human serum and urine.


Assuntos
Compostos de Anilina/química , Anti-Infecciosos/análise , Técnicas Eletroquímicas/métodos , Metronidazol/análise , Nanotubos de Carbono/química , Nitrogênio/química , Anti-Infecciosos/sangue , Anti-Infecciosos/urina , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cobalto/química , Cobre/química , Técnicas Eletroquímicas/instrumentação , Desenho de Equipamento , Humanos , Limite de Detecção , Metronidazol/sangue , Metronidazol/urina , Impressão Molecular/métodos , Nanopartículas/química , Nanotubos de Carbono/ultraestrutura , Óxidos/química , Reprodutibilidade dos Testes , Comprimidos
15.
Molecules ; 24(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340473

RESUMO

The use of cellulose nanocrystals (CNC) in high performance coatings is attractive for micro-scale structures or device fabrication due to the anisotropic geometry, however CNC are insulating materials. Carbon nanotubes (CNT) are also rod-shaped nanomaterials that display high mechanical strength and electrical conductivity. The hydrophobic regions of surface-modified CNC can interact with hydrophobic CNT and aid in association between the two anisotropic nanomaterials. The long-range electrostatic repulsion of CNC plays a role in forming a stable CNT and CNC mixture dispersion in water, which is integral to forming a uniform hybrid film. At concentrations favorable for film formation, the multiwalled nanotubes + CNC mixture dispersion shows cellular network formation, indicating local phase separation, while the single-walled nanotube + CNC mixture dispersion shows schlieren texture, indicating liquid crystal mixture formation. Conductive CNT + CNC hybrid films (5-20 µm thick) were cast on glass microscope slides with and without shear by blade coating. The CNT + CNC hybrid films electrical conductivity increased with increasing CNT loadings and some anisotropy was observed with the sheared hybrid films, although to a lesser extent than what was anticipated. Percolation models were applied to model the hybrid film conductivity and correlate with the hybrid film microstructure.


Assuntos
Celulose/química , Cristais Líquidos/química , Nanopartículas/química , Nanotubos de Carbono/química , Anisotropia , Celulose/ultraestrutura , Condutividade Elétrica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cristais Líquidos/ultraestrutura , Microscopia de Força Atômica , Nanopartículas/ultraestrutura , Nanotecnologia/métodos , Nanotubos de Carbono/ultraestrutura , Água/química
16.
Int J Mol Sci ; 20(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340560

RESUMO

BACKGROUND: Due to current antibiotic resistance worldwide, there is an urgent need to find new alternative antibacterial approaches capable of dealing with multidrug-resistant pathogens. Most recent studies have demonstrated the antibacterial activity and non-cytotoxicity of carbon nanomaterials such as graphene oxide (GO) and carbon nanofibers (CNFs). On the other hand, light-emitting diodes (LEDs) have shown great potential in a wide range of biomedical applications. METHODS: We investigated a nanotechnological strategy consisting of GO or CNFs combined with light-emitting diod (LED) irradiation as novel nanoweapons against two clinically relevant Gram-positive multidrug-resistant pathogens: methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE). The cytotoxicity of GO and CNFs was studied in the presence of human keratinocyte HaCaT cells. RESULTS: GO or CNFs exhibited no cytotoxicity and high antibacterial activity in direct contact with MRSE and MRSA cells. Furthermore, when GO or CNFs were illuminated with LED light, the MRSE and MRSA cells lost viability. The rate of decrease in colony forming units from 0 to 3 h, measured per mL, increased to 98.5 ± 1.6% and 95.8 ± 1.4% for GO and 99.5 ± 0.6% and 99.7 ± 0.2% for CNFs. CONCLUSIONS: This combined antimicrobial approach opens up many biomedical research opportunities and provides an enhanced strategy for the prevention and treatment of Gram-positive multidrug-resistant infections.


Assuntos
Antibacterianos/farmacologia , Grafite/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Nanoestruturas/química , Nanotubos de Carbono/química , Staphylococcus epidermidis/efeitos da radiação , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , Técnicas de Cocultura , Relação Dose-Resposta à Radiação , Humanos , Queratinócitos/citologia , Queratinócitos/fisiologia , Queratinócitos/efeitos da radiação , Luz , Resistência a Meticilina/efeitos da radiação , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos da radiação , Nanoestruturas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Fototerapia/métodos , Staphylococcus epidermidis/crescimento & desenvolvimento
17.
Int J Nanomedicine ; 14: 3245-3263, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190792

RESUMO

Background: Bacterial resistance to antibiotics is one of the biggest challenges facing medicine today. Anti-adhesive therapy, using inhibitors of bacterial adhesion to epithelial cells, one of the first stages of infection, is a promising approximation in this area. The size, shape, number of sugar and their placement are variables that have to be taken into account in order to develop multivalent systems able to inhibit the bacterial adhesion based on sugar-lectin interaction. Materials and methods: In the present work we report a modular approach for the synthesis of water-soluble 1D-carbon nanotube-sugar nanoconstructs, with the necessary flexibility to allow an efficient sugar-lectin interaction. The method is based on the reaction of aryl diazonium salts generated in situ from aniline-substituted mannose and lactose derivatives with single wall carbon nanotubes (SWCNTs) sidewalls. Results: Two hybrid nanosystems, I-II, exposing mannose or lactose and having a tetraethylene glycol spacer between the sugar and the nanotube sidewall were rapidly assembled and adequately characterized. The sweet nano-objects were then tested for their ability to agglutinate and selectively inhibit the growth of uropathogenic Escherichia coli. These studies have shown that nanosystem I, exposing mannose on the nanotube surface is able to agglutinate and to inhibit the bacterial growth unlike nano-objects II exposing lactose. Conclusion: The results reported constitute a proof of principle in using mannose-coated 1D-carbon nanotubes as antiadhesive drugs that compete for FimH binding and prevent the uropathogenic bacteria from adhering to the urothelial surface.


Assuntos
Escherichia coli/citologia , Nanotubos de Carbono/química , Aglutinação , Aderência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Manose/química , Nanotubos de Carbono/ultraestrutura , Polissacarídeos/síntese química , Polissacarídeos/química , Propriedades de Superfície
18.
Bioelectrochemistry ; 129: 144-153, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158799

RESUMO

A microbial fuel cell (MFC) is a potential bio-electrochemical technology that utilizes microorganisms to convert chemical energy into electrical energy. The low power output of MFCs remain the bottleneck for their practical applications. In this paper, a novel, biocompatible and bioelectrocatalytic composite chitosan-nitrogen doped carbon nanotubes-polyaniline (CS-NCNT-PANI) was prepared in situ on the 3D porous NCNT/sponge and applied to an MFC anode. The PANI was grafted on the CS-NCNT backbone to synthesize the ternary composite. This bioanode not only increased the active surface area and capacity but also facilitated bacterial adhesion and enrichment of microbes. Compared with the NCNT/sponge electrode, the charge transfer impedance of the ternary composite bioanode decreased from 14.07â€¯Ω to 2.25 Ω, and the maximum power density increased from 1.4 W·m-3 to 4.2 W·m-3; meanwhile, during the chronoamperometric experiment with a charge-discharge time of 60-60 min, the cumulative charge of the composite bioanode was 18,865.8 C·m-2, which is much higher than that of the NCNT/S anode (3625.3 C·m-2). High-throughput sequencing technology revealed that the ternary composite bioanode had good biocompatibility and high diversity. Therefore, this synthesized ternary composite is a promising candidate as a capacitive and biocompatible anode material in MFC.


Assuntos
Compostos de Anilina/química , Fontes de Energia Bioelétrica , Quitosana/química , Nanotubos de Carbono/química , Bactérias/genética , Bactérias/isolamento & purificação , Materiais Biocompatíveis/química , Fontes de Energia Bioelétrica/microbiologia , Biomassa , Eletricidade , Eletrodos/microbiologia , Nanotubos de Carbono/ultraestrutura , Filogenia , Porosidade
19.
Mater Sci Eng C Mater Biol Appl ; 102: 437-446, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147014

RESUMO

Owing to poor skin permeability, the transdermal (TRD) drug delivery at the required therapeutic rate still remains an arduous task. In the present investigation, a novel TRD enhancement strategy was introduced using the synergistic effect of gold nanoparticle (GNP) and skin electroporation. Diclofenac sodium (DS) was selected as a model drug. An electro-sensitive patch was constructed using skin adhesive matrix, polyvinyl alcohol/poly(dimethyl siloxane)-g-polyacrylate. GNP/carbon nanotube nanocomposite (GNP-CNT) was incorporated into the matrix with GNP and CNT to enhance skin permeability and electrical conductivity, respectively. Varying the concentration of GNP-CNT, alters the thermomechanical properties, water vapor permeability (WVP), drug encapsulation efficiency (DEE) and drug release profile, building a possibility to fine-tune the properties of the device. The membrane constructed with 1.5% GNP-CNT displayed the highest DEE and thermomechanical properties. The TRD DS release study was performed in rat skin at different GNP-CNT contents and variable conditions of applied voltage. Incorporating GNP-CNT enhanced the DS permeation profile with the best performance exhibited by device containing 1.5% nanofillers at an applied bias of 10.0 V. Electroporation in conjugation with GNP remarkably destroys the stratum corneum (SC) barrier by disparate mechanisms involving the breakdown of multilamellar lipid system, generation of new aqueous pathway and thermal effect. Furthermore, the dramatic disruption of lipid barriers generated by applied voltage was efficiently stabilized by GNP in addition to the transient and reversible openings created by them. Finally the safety of the device was confirmed by cell viability assay and environmental stability test. The developed skin permeation approach may open new avenues in TRD drug delivery.


Assuntos
Sistemas de Liberação de Medicamentos , Eletricidade , Eletroporação/métodos , Ouro/química , Nanopartículas Metálicas/química , Absorção Cutânea , Administração Cutânea , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Diclofenaco/farmacologia , Composição de Medicamentos , Liberação Controlada de Fármacos , Humanos , Nanopartículas Metálicas/ultraestrutura , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Permeabilidade , Ratos , Vapor , Propriedades de Superfície , Resistência à Tração , Termogravimetria
20.
Mater Sci Eng C Mater Biol Appl ; 102: 511-523, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147022

RESUMO

A fibrous scaffold, fully assimilating polyurethane (PU) and silk fibroin associated with functionalized multi-walled carbon nanotubes (fMWCNTs) was developed by electrospinning technique. Herein, we engineered the PU/Silk fibroin-fMWCNTs-based biomaterial that shows great promise as electrospun scaffolds for neuronal growth and differentiation, because of its unique mechanical properties, hydrophilicity, and biodegradability, with outstanding biocompatibility in nerve tissue engineering. The morphology and structural properties of the scaffolds were studied using various techniques. In particular, the presence of fMWCNTs enhances the electrical conductivity and plausible absorption of sufficient extracellular matrix (ECM). The in vitro tests revealed that the aligned scaffolds (PU/Silk-fMWCNTs) significantly stimulated the growth and proliferation of Schwann cells (S42), together with the differentiation and spontaneous neurite outgrowth of rat pheochromocytoma (PC12) cells that were particularly guided along the axis of fiber alignment. The conductive PU/Silk-fMWCNTs scaffold significantly improves neural expression in vitro with successful axonal regrowth, which was confirmed by immunocytochemistry and qRT-PCR analysis. Inspired by the comprehensive experimental results, the fMWCNTs-based scaffold affords new insight into nerve-guided conduit design from both conductive and protein rich standpoints, and opens a new perspective on peripheral nerve restoration in preclinical applications.


Assuntos
Condutividade Elétrica , Nanotubos de Carbono/química , Regeneração Nervosa/efeitos dos fármacos , Neurônios/fisiologia , Poliuretanos/farmacologia , Seda/farmacologia , Animais , Fenômenos Biomecânicos , Bombyx , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Nanofibras/química , Nanofibras/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Neurônios/efeitos dos fármacos , Células PC12 , Ratos , Estresse Mecânico , Tecidos Suporte/química , Água
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