Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.592
Filtrar
1.
Int J Nanomedicine ; 15: 7615-7626, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116491

RESUMO

Purpose: Although single-walled nanotubes (SWNTs) with functional groups have been suggested as a potential nanomedicine to treat neuronal disorders, effective routes to administer SWNTs have not been compared thus far. The blood-brain barrier is a considerable challenge for the development of brain-targeting drugs, and therefore functionalized SWNT routes of administration have been needed for testing Parkinson's disease (PD) treatment. Here, effective administration routes of functionalized SWNTs were evaluated in PD mouse model. Methods: Three different administration routes were tested in PD mouse model. Functionalized SWNTs were injected directly into the lateral ventricle three days before (Method 1) or after (Method 2) 6-hydroxydopamine (6-OHDA) injection to compare the protective effects of SWNTs against dopaminergic neuronal death or functionalized SWNTs were injected intravenously at three and four days after 6-OHDA injection (Method 3). Asymmetric behaviors and histological assessment from all animals were performed at two weeks after 6-OHDA injection. Results: Ventricular injections of SWNTs both before or after 6-OHDA exposure protected dopaminergic neurons both in the substantia nigra and striatum and alleviated rotational asymmetry behavior in PD mice. Moreover, intravenous administration of SWNTs three and four days after 6-OHDA injection also prevented neuronal death and PD mice behavioral impairment without apparent cytotoxicity after six months post-treatment. Conclusion: Our study demonstrates that functionalized SWNTs could effectively protect dopaminergic neurons through all administration routes examined herein. Therefore, SWNTs are promising nanomedicine agents by themselves or as therapeutic carriers to treat neuronal disorders such as PD.


Assuntos
Neurônios Dopaminérgicos/patologia , Nanotubos de Carbono/química , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Oxidopamina/toxicidade , Administração Intravenosa , Animais , Antioxidantes/farmacologia , Comportamento Animal , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos ICR , Nanotubos de Carbono/ultraestrutura , Crescimento Neuronal/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologia , Polietilenoglicóis/química , Tirosina 3-Mono-Oxigenase/metabolismo
2.
J Chromatogr A ; 1627: 461382, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823094

RESUMO

A method is described for the functionalization of magnetic carbon nanotubes to recognize aristolochic acid Ⅰ and Ⅱ. 3-Glycidyloxypropyltrimethoxysilane was used as a coupling agent to immobilize adenine on a solid support. The morphology and structure of adenine-coated magnetic carbon nanotubes was investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and a vibrating sample magnetometer (VSM). The adsorption performance of the adenine-coated magnetic carbon nanotubes was evaluated via adsorption isotherms, the kinetics and selectivity tests. The adsorption capacity of the adenine-functionalized sorbent for aristolochic acid Ⅰ was determined to be 24.5 µg mg-1. By combining magnetic solid phase extraction with HPLC detection, a method was developed to enrich and detect aristolochic acids used in traditional Chinese medicine. A satisfactory recovery (92.7 - 97.5% for aristolochic acid Ⅰ and 92.6 - 99.4% for aristolochic acid Ⅱ) and an acceptable relative standard deviation (<4.0%) were obtained.


Assuntos
Adenina/química , Ácidos Aristolóquicos/isolamento & purificação , Fenômenos Magnéticos , Nanotubos de Carbono/química , Adsorção , Medicamentos de Ervas Chinesas/química , Compostos Férricos/síntese química , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Cinética , Nanocompostos/química , Nanotubos de Carbono/ultraestrutura , Concentração Osmolar , Reprodutibilidade dos Testes , Dióxido de Silício/síntese química , Dióxido de Silício/química , Extração em Fase Sólida , Temperatura , Difração de Raios X
3.
Ecotoxicol Environ Saf ; 201: 110872, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32559693

RESUMO

Based on a hybrid carbon nanotube composite, a novel electrochemical sensor with high sensitivity and selectivity was designed for the simultaneous determination of dopamine (DA) and uric acid (UA). The hybrid carbon nanotube composite was prepared by ultrasonic assembly of carboxylated multi-walled carbon nanotube (MWCNT-COOH) and hydroxylated single-walled carbon nanotube (SWCNT-OH). And the hybrid (MWCNT-COOH/SWCNT-OH) composite was characterized by field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy. The electrochemical performances of MWCNT-COOH/SWCNT-OH composite modified glassy carbon electrode (MWCNT-COOH/SWCNT-OH/GCE) were analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Under the optimum experimental conditions, the as-prepared sensor showed high sensitivity and selectivity for DA and UA. The calibration curves obtained were linear for the currents versus DA and UA concentrations in the range 2-150 µM, and limits of detection (LODs) were calculated to be 0.37 µM and 0.61 µM (signal-to-noise ratio of 3, S/N = 3), respectively. The recoveries of DA and UA in bovine serum samples at MWCNT-COOH/SWCNT-OH/GCE were in the range 96.18-105.02%, and relative standard deviations (RSDs) were 3.34-7.27%. The proposed electrochemical sensor showed good anti-interference ability, excellent reproducibility and stability, as well as high selectivity, which might provide a promising platform for determination of DA and UA.


Assuntos
Dopamina/análise , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Ácido Úrico/análise , Animais , Carbono , Bovinos , Dopamina/sangue , Eletrodos , Limite de Detecção , Nanotubos de Carbono/ultraestrutura , Reprodutibilidade dos Testes , Ácido Úrico/sangue
4.
Int J Mol Sci ; 21(7)2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32218381

RESUMO

Currently, there is a lack of ultrasensitive diagnostic tool to detect some diseases such as ischemic stroke, thereby impacting effective and efficient intervention for such diseases at an embryonic stage. In addition to the lack of proper detection of the neurological diseases, there is also a challenge in the treatment of these diseases. Carbon nanotubes have a potential to be employed in solving the theragnostic challenges in those diseases. In this study, carbon nanotubes were successfully synthesized for potential application in the detection and treatment of the neurological diseases such as ischemic stroke. Vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) were purified with HCl, carboxylated with H2SO4:HNO3 (3:1) and acylated with SOCl2 for use in potential targeting studies and for the design of a carbon-based electrode for possible application in the diagnosis of neurological diseases, including ischemic stroke. MWCNTs were washed, extracted from the filter membranes and dried in a vacuum oven at 60 °C for 24 h prior to functionalization and PEGylation. CNTs were characterized by SEM, TEM, OCA, DLS, CV and EIS. The HCl-treated CNT obtained showed an internal diameter, outer diameter and thickness of 8 nm, 34 nm and 75 µm, while these parameters for the H2SO4-HNO3-treated CNT were 8 nm, 23 nm and 41µm, respectively. PEGylated CNT demonstrated zeta potential, polydispersive index and particle size distribution of 6 mV, 0.41 and 98 nm, respectively. VA-MWCNTs from quartz tube were successfully purified, carboxylated, acylated and PEGylated for potential functionalization for use in targeting studies. For designing the carbon-based electrode, VA-MWCNTs on silicon wafer were successfully incorporated into epoxy resin for diagnostic applications. Functionalized MWCNTs were nontoxic towards PC-12 neuronal cells. In conclusion, vertically super-aligned MWCNTs have been successfully synthesized and functionalized for possible theragnostic biomedical applications in neurological disorders such as ischemic stroke.


Assuntos
Nanotubos de Carbono , Eletrodos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Nanotubos de Carbono/ultraestrutura , Oxirredução , Tamanho da Partícula
5.
Nat Commun ; 11(1): 1332, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165612

RESUMO

Compared to transmission systems based on shafts and gears, tendon-driven systems offer a simpler and more dexterous way to transmit actuation force in robotic hands. However, current tendon fibers have low toughness and suffer from large friction, limiting the further development of tendon-driven robotic hands. Here, we report a super tough electro-tendon based on spider silk which has a toughness of 420 MJ/m3 and conductivity of 1,077 S/cm. The electro-tendon, mechanically toughened by single-wall carbon nanotubes (SWCNTs) and electrically enhanced by PEDOT:PSS, can withstand more than 40,000 bending-stretching cycles without changes in conductivity. Because the electro-tendon can simultaneously transmit signals and force from the sensing and actuating systems, we use it to replace the single functional tendon in humanoid robotic hand to perform grasping functions without additional wiring and circuit components. This material is expected to pave the way for the development of robots and various applications in advanced manufacturing and engineering.


Assuntos
Condutividade Elétrica , Seda/química , Aranhas/química , Tendões/fisiologia , Animais , Simulação por Computador , Retroalimentação , Humanos , Teste de Materiais , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Impressão Tridimensional , Robótica , Seda/ultraestrutura
6.
Life Sci ; 248: 117460, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092331

RESUMO

AIM: This study determined the optimum gamma irradiation dosage to sterilize sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and CNT functionalized with HY (HY-SWCNT and HY-MWCNT), evaluated the structural integrity of the materials and assessed whether sterilized materials kept biological properties without affecting renal function. MAIN METHODS: Materials were submitted to dosages of 100 gγ to 30 Kgγ and plated onto agar mediums for colony forming units (CFUs) counting. Sterilized samples were inoculated with 107Bacillus clausii, submitted again to gamma irradiation, and plated in agar mediums for CFUs counting. Scanning electron microscope was used for structural evaluation of sterilized materials. Tooth sockets of rats were treated with sterilized materials for bone formation assessment and renal function of the animals was analyzed. KEY FINDINGS: The optimum gamma dosage for sterilization was 250 gγ for HY and 2.5 Kgγ for the other materials without meaningful structural changes. Sterilized materials significantly increased bone formation (p < 0.05) and they did not compromise renal function and structure. SIGNIFICANCE: Gamma irradiation efficiently sterilized HY, SWCNT, MWCNT, HY-SWCNT and HY-MWCNT without affecting structural aspects while maintaining their desirable biological properties.


Assuntos
Materiais Dentários/efeitos da radiação , Raios gama , Ácido Hialurônico/efeitos da radiação , Nanotubos de Carbono/efeitos da radiação , Osteogênese/efeitos dos fármacos , Alvéolo Dental/efeitos dos fármacos , Animais , Bacillus clausii/efeitos da radiação , Contagem de Colônia Microbiana , Materiais Dentários/química , Materiais Dentários/farmacologia , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Testes de Função Renal , Masculino , Dente Molar/cirurgia , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Ratos , Ratos Wistar , Esterilização/métodos , Extração Dentária/métodos , Alvéolo Dental/microbiologia , Alvéolo Dental/fisiologia , Alvéolo Dental/cirurgia , Cicatrização/efeitos dos fármacos
7.
Talanta ; 209: 120595, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892044

RESUMO

MicroRNAs (miRNAs) appear as a novel reliable candidate in biomarkers for early diagnosis of cancer. Due to their roles in various types of cancer, their potential as a diagnostic biomarker is getting more attention. Here, a novel electrochemical biosensor for detection of miR-21 was demonstrated, through combining the advantages of electrochemical methods and nanomaterials with the selectivity of oligonucleotides, based on thiolated receptor probe-functionalized dendritic gold nanostructures (den-Au) via the self-assembly monolayer (SAM) process which grafted on the single-wall carbon nanotubes (SWCNTs) platform on the surface of the fluorine-doped tin oxide (FTO) electrode. Cadmium ions (Cd2+) were used as signal units and also signal amplification substance which labeled before on miR-21 target. The oxidation signal of Cd2+ as a signal unit was measured by differential pulse voltammetry (DPV) technique that had a very wide linear relationship with the concentration of miR-21 target (0.01 fmol L-1 to 1 µmol L-1) and low experimental detection limit of 0.01 fmol L-1. Furthermore, fabricated biosensor showed acceptable performance in human serum samples and also good selectivity indiscriminate between the complementary target and non-complementary one, so this nano-genosensor can clinically be used for prostate cancer diagnosis through the detection of miR-21 in human serum samples.


Assuntos
Ouro/química , MicroRNAs/sangue , Nanoestruturas/química , Nanotubos de Carbono/química , Neoplasias da Próstata/sangue , Adulto , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Humanos , Limite de Detecção , Masculino , Nanoestruturas/ultraestrutura , Nanotubos de Carbono/ultraestrutura
8.
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
9.
Mater Sci Eng C Mater Biol Appl ; 108: 110376, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924027

RESUMO

As potential alternatives to conventional semiconductor quantum dots, fluorescent carbon quantum dots (CQDs) have received increasing research attention in biomedical fields owing to their splendid advantages of low cytotoxicity, strong fluorescence and excellent water dispersion. However, the preparation procedures of CQDs with designable chemical properties and functions are complicated and low efficient. In this work, we developed a facile, economical and straightforward strategy to prepare CQDs by a one-step thiol-ene click reaction between multiwalled carbon nanotubes (CNTs) and thiomalic acid (TA). The successful synthesis of CQDs was confirmed by a series of characterization data. The results manifested that CQDs were well combined with TA through surface thiol-ene click chemistry. In addition, the optical property is also desirable, the maximum emission wavelength was located in 500 nm and CQDs still could emit strong blue fluorescent light after irradiation with UV irradiation for 3 h. Besides, the pH value makes no significant changes for fluorescence emission wavelength of CQDs and CQDs can emit strongest fluorescence in weak acid solution. Furthermore, CQDs could be internalized by cells and show great cell dyeing performance and low cytotoxicity. All these features imply that TA functionalized CQDs possess great potential for biological imaging. The one-step thiol-ene click strategy provided a novel tool to prepare functionalized CQDs with great potential for biomedical applications.


Assuntos
Química Click/métodos , Nanotubos de Carbono/química , Pontos Quânticos/química , Animais , Morte Celular , Linhagem Celular , Fluorescência , Camundongos , Nanotubos de Carbono/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética , Pontos Quânticos/ultraestrutura
10.
Mater Sci Eng C Mater Biol Appl ; 108: 110374, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924043

RESUMO

The development of highly biomimetic scaffolds in terms of composition and structures, to repair or replace damaged bone tissues, is particularly relevant for tissue engineering. This paper investigates a 3D printed porous scaffold containing aligned multi-walled carbon nanotubes (MWCNTs) and nano-hydroxyapatite (nHA), mimicking the natural bone tissue from the nanoscale to macroscale level. MWCNTs with similar dimensions as collagen fibres are coupled with nHA and mixed within a polycaprolactone (PCL) matrix to produce scaffolds using a screw-assisted extrusion-based additive manufacturing system. Scaffolds with different material compositions were extensively characterised from morphological, mechanical and biological points of views. Transmission electron microscopy and polarised Raman spectroscopy confirm the presence of aligned MWCNTs within the printed filaments. The PCL/HA/MWCNTs scaffold are similar to the nanostructure of native bone and shows overall increased mechanical properties, cell proliferation, osteogenic differentiation and scaffold mineralisation, indicating a promising approach for bone tissue regeneration.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Durapatita/farmacologia , Nanotubos de Carbono/química , Osteogênese/efeitos dos fármacos , Poliésteres/farmacologia , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colágeno/metabolismo , Humanos , Nanotubos de Carbono/ultraestrutura , Osteocalcina/metabolismo , Análise Espectral Raman
11.
J Nanobiotechnology ; 18(1): 11, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931815

RESUMO

BACKGROUND: In several years ago, infection with human papillomaviruses (HPVs), have been prevalent in the worlds especially HPV type 18, can lead to cervical cancer. Therefore, rapid, accurate, and early diagnosis of HPV for successful treatment is essential. The present study describes the development of a selective and sensitive electrochemical biosensor base on DNA, for early detection of HPV-18. For this purpose, a nanocomposite of reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) were electrodeposited on a screen-printed carbon electrode (SPCE). Then, Au nanoparticles (AuNPs) were dropped on a modified SPCE. Subsequently, single strand DNA (ssDNA) probe was immobilized on the modified electrode. The link attached between AuNPs and probe ssDNA provided by L-cysteine via functionalizing AuNPs (Cys-AuNPs). The differential pulse voltammetry (DPV) assay was also used to electrochemical measurement. The measurement was based on the oxidation signals of anthraquninone-2-sulfonic acid monohydrate sodium salt (AQMS) before and after hybridization between the probe and target DNA. RESULTS: The calibration curve showed a linear range between 0.01 fM to 0.01 nM with a limit of detection 0.05 fM. The results showed that the optimum concentration for DNA probe was 5 µM. The good performance of the proposed biosensor was achieved through hybridization of DNA probe-modified SPCE with extracted DNA from clinical samples. CONCLUSIONS: According to the investigated results, this biosensor can be introduced as a proprietary, accurate, sensitive, and rapid diagnostic method of HPV 18 in the polymerase chain reaction (PCR) of real samples.


Assuntos
Técnicas Biossensoriais , DNA Viral/análise , Detecção Precoce de Câncer , Técnicas Eletroquímicas/métodos , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/isolamento & purificação , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Calibragem , Espectroscopia Dielétrica , Eletrodos , Feminino , Ouro , Humanos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Nat Biomed Eng ; 4(2): 159-171, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31659307

RESUMO

Mechanical mismatches between implanted electronics and biological tissues can lead to inaccurate readings and long-term tissue damage. Here, we show that functionalized multi-walled carbon nanotubes twisted into helical fibre bundles that mimic the hierarchical structure of muscle can monitor multiple disease biomarkers in vivo. The flexible fibre bundles are injectable, have a low bending stiffness and display ultralow stress under compression. As proof-of-concept evidence of the sensing capabilities of these fibre bundles, we show that the fibre bundles enable the spatially resolved and real-time monitoring of H2O2 when implanted in tumours in mice, and that they can be integrated with a wireless transmission system on an adhesive skin patch to monitor calcium ions and glucose in the venous blood of cats for 28 d. The versatility of the helical fibre bundles as chemically functionalized electrochemical sensors makes them suitable for multiple sensing applications in biomedicine and healthcare.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Diabetes Mellitus Tipo 1/metabolismo , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono , Neoplasias/metabolismo , Animais , Materiais Biocompatíveis , Biomarcadores/metabolismo , Biomarcadores Tumorais/metabolismo , Gatos , Diabetes Mellitus Tipo 1/diagnóstico , Feminino , Peróxido de Hidrogênio/análise , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Monitorização Fisiológica , Nanotubos de Carbono/ultraestrutura , Neoplasias/diagnóstico
13.
ACS Appl Mater Interfaces ; 12(2): 2903-2909, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31851480

RESUMO

A novel signal-on chemiluminescence (CL) assay for pyrophosphatase (PPase) activity determination was innovatively developed based on the Cu(II)-regulated on-site assembly of highly chemiluminescent Cu(II), N-(aminobutyl)-N-(ethylisoluminol) (ABEI), gold nanodot, and chitosan multifunctionalized carbon nanotubes (Cu(II)/ABEI-Au/cs-CNTs). First, ABEI-functionalized gold nanodots (ABEI-Au) were assembled on the surface of chitosan-modified carbon nanotubes (cs-CNTs) via the reduction of HAuCl4 with ABEI in a cs-CNT suspension to form ABEI-Au/cs-CNTs. Then, it was found that the catalyst Cu(II) can be selectively, efficiently, and quickly adsorbed onto ABEI-Au/cs-CNTs via the high-affinity interactions between Cu(II) and cs-CNTs to form novel hybrid nanomaterials Cu(II)/ABEI-Au/cs-CNTs. The CL intensity of Cu(II)/ABEI-Au/cs-CNTs was enhanced by about 2 orders of magnitude compared with that of ABEI-Au/cs-CNTs. Furthermore, it was found that in the presence of pyrophosphate ions (PPi), PPi could coordinate with Cu(II) to form a stable PPi-Cu(II) complex and block the assembly of Cu(II)/ABEI-Au/cs-CNTs. After the addition of PPase, PPase could catalyze the hydrolysis of PPi into Pi and release Cu(II) from the PPi-Cu(II) complex. The released free Cu(II) could trigger the on-site assembly of highly chemiluminescent Cu(II)/ABEI-Au/cs-CNTs, resulting in an enhanced CL intensity. The enhanced CL intensity had a good linear relationship with the activity units of PPase ranging from 0.025 to 0.5 U, with a detection limit of 9 mU. The method was employed to monitor the PPase inhibitor efficiently. Cu(II)/ABEI-Au/cs-CNTs with excellent CL may also find more applications in the development of novel CL analytical methods.


Assuntos
Cobre/química , Pirofosfatase Inorgânica/análise , Medições Luminescentes , Nanotubos de Carbono/química , Quitosana/química , Íons , Cinética , Luminol/análogos & derivados , Luminol/síntese química , Luminol/química , Nanotubos de Carbono/ultraestrutura , Espectroscopia Fotoeletrônica
14.
Biosens Bioelectron ; 148: 111764, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31707325

RESUMO

We are reporting an original supramolecular architecture based on a rationally designed new nanohybrid with enhanced peroxidase-like activity and site-specific biorecognition properties using avidin-functionalized multi-walled carbon nanotubes (MWCNTs-Av) and Ru nanoparticles (RuNPs). The nanohybrid-electrochemical interface was obtained by drop-coating of MWCNTs-Av dispersion at glassy carbon electrodes (GCE) followed by solvent evaporation and further electrodeposition of RuNPs (50 ppm RuCl2 for 15 s at -0.600 V). The simultaneous presence of MWCNTs and RuNPs produces a synergic effect on the non-enzymatic catatalytic reduction of H2O2 and allows the quantification of H2O2 in a wide linear range (from 5.0 × 10-7 M to 1.75 × 10-3 M) with a low limit of detection (65 nM). The avidin residues present in MWCNTs-Av/RuNPs hybrid nanomaterial allowed the anchoring by bioaffinity of biotinylated glucose oxidase (biot-GOx) as proof-of-concept of the analytical application of MWCNTs-Av platform for biosensors development. The resulting nanoarchitecture behaves as a bienzymatic-like glucose biosensor with a competitive analytical performance: linear range between 2.0 × 10-5 M and 1.23 × 10-3 M, sensitivity of (0.343 ±â€¯0.002) µA mM-1 or (2.60 ±â€¯0.02) µA mM-1 cm-2, detection limit of 3.3 µM, and reproducibility of 5.2% obtained with five different GCE/MWCNTs-Av/RuNPs/biot-GOx bioplatforms prepared the same day using the same MWCNTs-Av dispersion, and 9.1% obtained with nine biosensors prepared in different days with nine different MWCNTs-Av dispersions. The average concentrations of glucose in Gatorade®, Red bull® and Pepsi® with the biosensor demonstrated excellent agreement with those reported in the commercial beverages.


Assuntos
Avidina/química , Técnicas Biossensoriais/métodos , Nanopartículas/química , Nanotubos de Carbono/química , Rutênio/química , Aspergillus niger/enzimologia , Bebidas/análise , Materiais Biomiméticos/química , Biotinilação , Catálise , Técnicas Eletroquímicas/métodos , Glucose/análise , Glucose Oxidase/química , Peróxido de Hidrogênio/análise , Limite de Detecção , Nanopartículas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Peroxidase/química
15.
Int J Biol Macromol ; 144: 389-402, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843603

RESUMO

In this study, the bioactivity of glutaraldehyde (GA)-crosslinked chitosan (CS)/poly(vinyl alcohol) (PVA)/ascorbic acid (ASC)-multiwalled carbon nanotube (MWCNTs) nanocomposites (NCs) was investigated. These NCs were fabricated via incorporation of 3, 5, and 7 wt% of ASC-MWCNTs into CS/PVA blend using ultrasonication. The polymeric matrix was crosslinked using a low amount of GA to fabricate completely water-insoluble NCs with high tolerance against the dynamic and static stress of body fluid environment. The synthesized NCs were characterized via various techniques. The field emission scanning electron microscopy studies showed the homogenous distribution of nanofiller throughout the matrix. The results of the thermogravimetric analysis demonstrated that the fabricated NCs have greater thermal stability than GA-crosslinked CS/PVA. The bioactivity was studied using in vitro test via immersion of samples in simulated body fluid (SBF) for 30 days. The results showed that the GA-crosslinked CS/PVA/ASC-MWCNTs NC 3 wt% has good hydroxyapatite-forming ability in SBF solution.


Assuntos
Ácido Ascórbico/química , Quitosana/química , Durapatita/química , Glutaral/química , Nanocompostos/química , Nanotubos de Carbono/química , Microscopia Eletrônica de Varredura , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Álcool de Polivinil/química , Engenharia Tecidual
16.
Int J Biol Macromol ; 145: 262-271, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31870866

RESUMO

Nowadays 3D bioprinting, due to its high structural reconstruction and low cost, has been a promising technology and gained expectation in the treatment of vascular diseases. Although some studies have reported that 3D printing of large-sized blood vessels in the human body has been achieved, there are still some problems to be solved urgently, such as the unfulfilled microvascular simulation and inferior biocompatibility and mechanical strength of scaffold materials. In this paper, the hybrid bioink prepared with gelatin, sodium alginate and carbon nanotubes were manufactured into cylindrical scaffolds through the collaboration between the vertical directional extrusion of printing nozzle and axial rotation of stepper motor module. Mouse epidermal fibroblasts were inoculated into the inner and outer walls of hollow tubular scaffolds to fabricate engineered blood vessels. The internal diameters of the bionic circular tubes printed in batches were 3 mm with an average wall thickness of 0.5 mm and a length of 7-10 cm. Results demonstrated that the proper doping of carbon nanotubes could effectively increase the mechanical properties of the composite scaffolds. Also, quantitative experiments proved that a small amount of doping of carbon nanotubes had little effect on cytotoxicity, and the constructs could meet the requirements of biomimetic vascular.


Assuntos
Alginatos/farmacologia , Materiais Biomiméticos/química , Bioimpressão/métodos , Fibroblastos/efeitos dos fármacos , Gelatina/farmacologia , Nanotubos de Carbono/química , Alginatos/química , Animais , Materiais Biomiméticos/farmacologia , Bioimpressão/instrumentação , Prótese Vascular , Vasos Sanguíneos/citologia , Fibroblastos/citologia , Gelatina/química , Tinta , Camundongos , Nanotubos de Carbono/ultraestrutura , Cultura Primária de Células , Impressão Tridimensional/instrumentação , Pele/citologia , Pele/efeitos dos fármacos , Engenharia Tecidual/métodos , Tecidos Suporte
17.
Int J Nanomedicine ; 14: 9285-9294, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819430

RESUMO

Purpose: Physicochemical properties play a crucial role in determining the toxicity of multi-walled carbon nanotubes (MWCNTs). Recently we found that MWCNTs with longer length and smaller diameters could induce toxicity to human umbilical vein endothelial cells (HUVECs) through the activation of endoplasmic reticulum (ER) stress. In this study, we further investigated the possible contribution of hydroxylation and carboxylation to the cytotoxicity of MWCNTs. Methods: The HUVECs were exposed to pristine (code XFM19), hydroxylated (code XFM20; content of hydroxyl groups 1.76 wt%) and carboxylated (code XFM21; content of carboxyl groups 1.23 wt%) MWCNTs, respectively. Then, the internalization, cytotoxicity, oxidative stress and activation of apoptosis-ER stress pathway were measured. Results: In consequence, all types of MWCNTs could be internalized into the HUVECs, and the cellular viability was significantly reduced to a similar level. Moreover, the MWCNTs increased intracellular reactive oxygen species (ROS) and decreased glutathione (GSH) to similar levels, indicating their capacity of inducing oxidative stress. The Western blot results showed that all types of MWCNTs reduced BCL-2 and increased caspase-3, caspase-8, cleaved caspase-3 and cleaved caspase-8. The expression of ER stress gene DNA damage-inducible transcript 3 (DDIT3) and protein level of chop were only significantly induced by XFM20 and XFM21, whereas protein level of p-chop was promoted by XFM19 and XFM21. In addition, the pro-survival gene XBP-1s was significantly down-regulated by all types of MWCNTs. Conclusion: These results suggested that MWCNTs could induce cytotoxicity to HUVECs via the induction of oxidative stress and apoptosis-ER stress, whereas a low degree of hydroxylation or carboxylation did not affect the toxicity of MWCNTs to HUVECs.


Assuntos
Apoptose , Estresse do Retículo Endoplasmático , Nanotubos de Carbono/química , Sobrevivência Celular , Endocitose , Estresse do Retículo Endoplasmático/genética , Glutationa/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hidrodinâmica , Nanotubos de Carbono/ultraestrutura , Estresse Oxidativo , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
18.
Int J Nanomedicine ; 14: 9295-9306, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819431

RESUMO

Background: The advent of 3D printing technology allowed the realization of custom devices that can be used not only in the everyday life but also in the nanotechnology and biomedical fields. In nanotechnology, the use of bi-dimensional nanostructures based on carbon nanotubes, generally referred as buckypapers, have received considerable attention for their versatility and potential application in many biomedical fields. Unfortunately, buckypapers are extremely hydrophobic and cannot be used in aqueous media to culture cells. Methods: A polymeric device able to accommodate buckypapers and facilitate cell growth was fabricated by using 3D printing technology. We imparted hydrophilicity to buckypapers by coating them with polyamidoamine (PAMAM) dendrimers. Results: We found that by using novel techniques such as polymer coating the buckypaper hydrophilicity increased, whereas the use of 3D printing technology allowed us to obtain custom devices that have been used to culture cells on buckypapers for many days. We characterized in details the morphology of these structures and studied for the first time the kinetic of cell proliferation. We found that these scaffolds, if properly functionalized, are suitable materials to grow cells for long time and potentially employable in the biomedical field. Conclusion: Although these materials are cytotoxic under certain circumstances, we have found a suitable coating and specific experimental conditions that encourage using buckypapers as novel scaffolds for cell growth and for potential applications in tissue repair and regeneration.


Assuntos
Tecnologia Biomédica/métodos , Técnicas de Cultura de Células/instrumentação , Dendrímeros/química , Nanotubos de Carbono/química , Impressão Tridimensional/instrumentação , Linhagem Celular , Proliferação de Células , Humanos , MicroRNAs/metabolismo , Nanotubos de Carbono/ultraestrutura , Propriedades de Superfície
19.
Nat Nanotechnol ; 14(12): 1143-1149, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31712665

RESUMO

Affinity-based electrochemical detection in complex biological fluids could enable multiplexed point-of-care diagnostics for home healthcare; however, commercialization of point-of-care devices has been limited by the rapid loss of sensitivity caused by electrode surface inactivation and biofouling. Here, we describe a simple and robust antifouling coating for electrodes consisting of a three-dimensional porous matrix of cross-linked bovine serum albumin supported by a network of conductive nanomaterials composed of either gold nanowires, gold nanoparticles or carbon nanotubes. These nanocomposites prevent non-specific interactions while enhancing electron transfer to the electrode surface, preserving 88% of the original signal after 1 month of exposure to unprocessed human plasma, and functionalization with specific antibodies enables quantification of anti-interleukin 6 in plasma with high sensitivity. The easy preparation, stability and simplicity of this nanocomposite allow the generation of electrochemical biosensors that can operate in complex biological fluids such as blood plasma or serum.


Assuntos
Técnicas Biossensoriais/instrumentação , Ouro/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Soroalbumina Bovina/química , Anticorpos/sangue , Incrustação Biológica , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Humanos , Proteínas Imobilizadas/química , Modelos Moleculares , Nanotubos de Carbono/ultraestrutura , Plasma/química
20.
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
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA