RESUMO
In anaerobic bioreactors, the electrons produced during the oxidation of organic matter can potentially be used for the biological reduction of pharmaceuticals in wastewaters. Common electron transfer limitations benefit from the acceleration of reactions through utilization of redox mediators (RM). This work explores the potential of carbon nanomaterials (CNM) as RM on the anaerobic removal of ciprofloxacin (CIP). Pristine and tailored carbon nanotubes (CNT) were first tested for chemical reduction of CIP, and pristine CNT was found as the best material, so it was further utilized in biological anaerobic assays with anaerobic granular sludge (GS). In addition, magnetic CNT were prepared and also tested in biological assays, as they are easier to be recovered and reused. In biological tests with CNM, approximately 99% CIP removal was achieved, and the reaction rates increased ≈1.5-fold relatively to the control without CNM. In these experiments, CIP adsorption onto GS and CNM was above 90%. Despite, after applying three successive cycles of CIP addition, the catalytic properties of magnetic CNT were maintained while adsorption decreased to 29 ± 3.2%, as the result of CNM overload by CIP. The results suggest the combined occurrence of different mechanisms for CIP removal: adsorption on GS and/or CNM, and biological reduction or oxidation, which can be accelerated by the presence of CNM. After biological treatment with CNM, toxicity towards Vibrio fischeri was evaluated, resulting in ≈ 46% detoxification of CIP solution, showing the advantages of combining biological treatment with CNM for CIP removal.
Assuntos
Ciprofloxacina/metabolismo , Elétrons , Nanopartículas de Magnetita/química , Nanotubos de Carbono/química , Esgotos/microbiologia , Poluentes Químicos da Água/metabolismo , Adsorção , Aliivibrio fischeri/efeitos dos fármacos , Aliivibrio fischeri/crescimento & desenvolvimento , Anaerobiose/fisiologia , Biodegradação Ambiental , Reatores Biológicos , Ciprofloxacina/isolamento & purificação , Humanos , Nanopartículas de Magnetita/ultraestrutura , Methanobacterium/metabolismo , Methanobrevibacter/metabolismo , Methanosarcinales/metabolismo , Methanospirillum/metabolismo , Testes de Sensibilidade Microbiana , Nanotubos de Carbono/ultraestrutura , Oxirredução , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
With the increase in demand, artificially planting Chinese medicinal materials (CHMs) has also increased, and the ensuing pesticide residue problems have attracted more and more attention. An optimized quick, easy, cheap, effective, rugged and safe (QuEChERS) method with multi-walled carbon nanotubes as dispersive solid-phase extraction sorbents coupled with surface-enhanced Raman spectroscopy (SERS) was first proposed for the detection of deltamethrin in complex matrix Corydalis yanhusuo. Our results demonstrate that using the optimized QuEChERS method could effectively extract the analyte and reduce background interference from Corydalis. Facile synthesized gold nanoparticles with a large diameter of 75 nm had a strong SERS enhancement for deltamethrin determination. The best prediction model was established with partial least squares regression of the SERS spectra ranges of 545~573 cm-1 and 987~1011 cm-1 with a coefficient of determination (R2) of 0.9306, a detection limit of 0.484 mg/L and a residual predictive deviation of 3.046. In summary, this article provides a new rapid and effective method for the detection of pesticide residues in CHMs.
Assuntos
Corydalis/química , Nanotubos de Carbono/química , Nitrilas/análise , Resíduos de Praguicidas/análise , Piretrinas/análise , Análise Espectral Raman , Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/química , Modelos Moleculares , Estrutura Molecular , Nanotubos de Carbono/ultraestrutura , Nitrilas/química , Nitrilas/isolamento & purificação , Resíduos de Praguicidas/química , Resíduos de Praguicidas/isolamento & purificação , Piretrinas/química , Piretrinas/isolamento & purificação , Reprodutibilidade dos TestesRESUMO
A method is described for the functionalization of magnetic carbon nanotubes to recognize aristolochic acid â and â ¡. 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 â 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 â and 92.6 - 99.4% for aristolochic acid â ¡) 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 XRESUMO
The porous chitosan/carboxylated carbon nanotubes composite aerogels (CS-CCN) with different CCN contents were prepared for the efficient removal of U(VI) from aqueous solution. The successful formation of CS-CCN aerogels with highly porous structure was confirmed by different characterizations (such as SEM, TEM, XRD, etc.). The sorption capacity of the aerogels depends on CCN content, which has significant impact on the porous structure and the sorption ability of the aerogels. The CS-CCN aerogels were found to be very effective for U(VI) sorption: the maximum mono-layer sorption capacity for CS-CCN2 aerogel reached 307.5 mg/g at pH 5.0 and 298 K. The chemisorption or surface complexation through sharing of O/N lone pair electrons on the active sites (carboxylic and amine groups) was responsible for U(VI) sorption, which is confirmed by the IR and XPS analysis. Meanwhile, the good-fitting of both sorption kinetics by pseudo-second-order model and sorption isotherms by Langmuir model also indicates chemisorption mechanism. The thermodynamic data suggest that U(VI) sorption on CS-CCN aerogel is endothermic and spontaneous. The unique characteristics such as high sorption capacity, fast kinetic, and easy recovery from solution make CS-CCN aerogels be very efficient sorbents for the treatment of radioactive wastewater.
Assuntos
Quitosana/química , Géis/química , Nanotubos de Carbono/química , Urânio/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Nanotubos de Carbono/ultraestrutura , Porosidade , Soluções , Análise EspectralRESUMO
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 Fármacos , 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 EstáticaRESUMO
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/ultraestruturaRESUMO
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 µgâmg-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 µgâmg-1 for AAI with a correlation coefficient (R2) of 0.9998. The limit of detection (LOD, S/N=3) was 0.034 µgâmg-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 , Difração de Raios XRESUMO
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 & desenvolvimentoRESUMO
Phototherapy has been offered as an alternative and promising antibacterial strategy to overcome the antibiotic resistance problem. This study evaluated the antibacterial and phototherapy effects of carbon nanotubes with a polypyrrole coating in a core@shell structure (CNTs@PPy) on Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa was treated with CNTs@PPy at different concentrations (50-500 µg mL-1) in dark or laser light irradiation with a wavelength of 808 nm, a power density of 1000 mW cm-2 for 20 min. Temperature increment, cell viability, formation of reactive oxygen species (ROS) and protein/nucleic acid leakage subsequent the P. aeruginosa treatment were evaluated. The results showed that near-infrared laser irradiation of CNTs@PPy caused to a temperature increment confirming the ability of powerful photokilling of P. aeruginosa in a photothermal route. On the other hand, while CNTs@PPy represented just a 30-50% P. aeruginosa killing rate in dark, laser irradiation of 250 and 500 µg mL-1 concentrations of CNTs@PPy resulted in a Ë70% P. aeruginosa killing rate, along with significant ROS production into the medium and protein and nucleic acid leakage from P. aeruginosa. These later effects were assigned to a photodynamic route activity of CNTs@PPy upon laser irradiation. Therefore, CNTs@PPy acted as a photosensitizer in both photothermal and photodynamic therapies to present an enhanced bactericidal activity to annihilate and destroyed the gram-negative bacteria P. aeruginosa, a cause of many infectious diseases.
Assuntos
Terapia a Laser , Nanotubos de Carbono/química , Fármacos Fotossensibilizantes/farmacologia , Polímeros/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos da radiação , Pirróis/química , Contagem de Colônia Microbiana , Fluorescência , Nanotubos de Carbono/ultraestrutura , Pseudomonas aeruginosa/crescimento & desenvolvimento , TemperaturaRESUMO
Acetylcholinesterase (AChE) biosensor technology is widely applied in the detection of organophosphate pesticides in agricultural production via the inhibition of AChE activity by organophosphates. However, the AChE electrode has some drawbacks, such as low stability and high overpotential. Combining the advantages of multiwalled carbon nanotubes (MWCNTs) and ionic liquids, we constructed a novel bienzyme electrode [Cl/iron porphyrin (FePP)-modified MWCNTs/AChE/glassy carbon electrode], which included AChE and mimetic oxidase FePP. In this electrode, FePP is covalently bound to the AChE carrier via ionic liquid for increased electrode sensitivity and stability. Under optimal conditions, this novel biosensor has a monocrotophos detection limit of 3.2 × 10-11 mol/L and good recovery of 89-104%. After 5 weeks of storage at 4 °C, the oxidation current was 97.8% of its original value. The biosensor has high stability and sensitivity for monocrotophos detection and is a promising device for monitoring food safety. Graphical abstract The complete synthesis process of Cl/FePP-MWCNTs/AChE/GCE.
Assuntos
Acetilcolinesterase/química , Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/química , Metaloporfirinas/química , Monocrotofós/análise , Nanotubos de Carbono/química , Praguicidas/análise , Materiais Biomiméticos/química , Brassica/química , Líquidos Iônicos/química , Compostos de Ferro/química , Lactuca/química , Limite de Detecção , Nanotubos de Carbono/ultraestrutura , Cebolas/químicaRESUMO
Metastasis is the major cause of cancer-death. Checkpoint inhibition shows great promise as an immunotherapeutic treatment for cancer patients. However, most currently available checkpoint inhibitors have low response rates. To augment the antitumor efficacy of checkpoint inhibitors, such as CTLA-4 antibodies, a single-walled carbon nanotube (SWNT) modified by a novel immunoadjuvant, glycated chitosan (GC), was used for the treatment of metastatic mammary tumors in mice. We treated the primary tumors by intratumoral administration of SWNT-GC, followed with irradiation with a 1064-nm laser to achieve local ablation through photothermal therapy (PTT). The treatment induced a systemic antitumor immunity which inhibited lung metastasis and prolonged the animal survival time of treated. Combining SWNT-GC-laser treatment with anti-CTLA-4 produced synergistic immunomodulatory effects and further extended the survival time of the treated mice. The results showed that the special combination, PTTâ¯+â¯SWNT-GCâ¯+â¯anti-CTLA, could effectively suppress primary tumors and inhibit metastases, providing a new treatment strategy for metastatic cancers.
Assuntos
Neoplasias da Mama/imunologia , Neoplasias da Mama/terapia , Imunoterapia , Nanotubos de Carbono/química , Fototerapia , Animais , Apoptose , Linhagem Celular Tumoral , Quitosana/química , Feminino , Humanos , Imunidade , Camundongos Endogâmicos BALB C , Nanotubos de Carbono/ultraestrutura , Metástase NeoplásicaRESUMO
A highly sensitive electrochemical biosensor for detection of platelet-derived growth factor-BB (PDGF-BB) is developed by using Se-doped multi-walled carbon nanotubes (MWCNTs)-graphene hybrids as electrode supporting substrate, hemin/G-quadruplex as trace labels and Y-shaped DNA-aided target recycling as signal magnifier. The aptamer-containing hairpin probes were first immobilized on the electrode. When target PDGF-BB was added, the aptamer binded PDGF-BB to trigger catalytic assembly of two other hairpins to form many G-quadruplex Y-junction DNA structures, which released PDGF-BB to again bind the intact aptamer to initiate another assembly cycle. G-quadruplex/hemin complexes were produced when hemin was added to generate substantially amplified current output. The developed assay showed a linear range toward PDGF-BB from 0.1 pM to 10 nM with a detection limit of 27 fM (S/N = 3). The method showed excellent specificity and repeatability, and could be expediently applied for sensitive detection of other molecules by simply changing the aptamers.
Assuntos
Técnicas Biossensoriais/métodos , DNA/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Nanotubos de Carbono/química , Selênio/química , Animais , Aptâmeros de Nucleotídeos/química , Becaplermina/sangue , Bovinos , Quadruplex G , Hemina/química , Humanos , Nanotubos de Carbono/ultraestrutura , Reprodutibilidade dos TestesRESUMO
Chemotherapy and photothermal therapy can be efficiently integrated to achieve enhanced antitumor efficacy by using carbon nanotubes (CNTs) which are super in delivering drug and converting near infrared radiation (NIR) into heat. We previously developed an innovative TAT-chitosan functionalized MWCNTs (MWCNTs/TC) based drug delivery system for doxorubicin (DOX) and preliminarily investigated its release profile and antitumor effect. In the present study, the application potential of MWCNTs/DOX/TC in chemo-photothermal combination therapy was further explored. The in vitro drug release, photothermal effect, cellular uptake and cytotoxicity were assessed. The in vivo anti-tumor effect of MWCNTs/DOX/TC was further evaluated by noninvasive bioluminescence imaging. It was demonstrated that this innovative drug delivery system not only realized a conspicuously sustained release of DOX, but also retained the optical properties of MWCNTs for a high photothermal effect upon NIR irradiation, and exhibited remarkably enhanced anti-tumor efficacy through the synergistic function of chemotherapy and photothermal ablation.
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Quitosana/análogos & derivados , Doxorrubicina/uso terapêutico , Nanotubos de Carbono/química , Neoplasias/terapia , Animais , Antibióticos Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Quitosana/uso terapêutico , Terapia Combinada/métodos , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Hipertermia Induzida/métodos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanotubos de Carbono/ultraestrutura , Fototerapia/métodosRESUMO
The prevalence of cardiac malignant neoplasms in the general population has been shown to be significant higher than what was previously estimated, yet their treatment has remained difficult and effective therapies are lacking. In the current study, we developed a novel thermotherapy in which PEG-functionalized carbon nanotubes were injected into the tumor regions to assist in the targeted delivery of infrared radiation energy with minimal hyperthermic damage to the surrounding normal tissues. In a mouse model of cardiac malignant neoplasms, the injected carbon nanotubes could rapidly induce coagulative necrosis of tumor tissues when exposed to infrared irradiation. In accordance, the treatment was also found to result in a restoration of heart functions and a concomitant increase of survival rate in mice. Taken together, our carbon nanotube-based thermotherapy successfully addressed the difficulty facing conventional laser ablation methods with regard to off-target thermal injury, and could pave the way for the development of more effective therapies against cardiac malignant neoplasms.
Assuntos
Neoplasias Cardíacas/terapia , Animais , Materiais Biocompatíveis/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Testes de Função Cardíaca , Neoplasias Cardíacas/fisiopatologia , Humanos , Hipertermia Induzida , Injeções , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Polietilenoglicóis/química , Análise de Sobrevida , Temperatura , Carga Tumoral/efeitos dos fármacosRESUMO
The choice of electrode material is of paramount importance in neural prosthetic devices. Electrodes must be biocompatible yet able to sustain repetitive current injections in a highly corrosive environment. We explored the suitability of carbon nanotube (CNT) electrodes to stimulate retinal ganglion cells (RGCs) in a mouse model of outer retinal degeneration. We investigated morphological changes at the bio-hybrid interface and changes in RGC responses to electrical stimulation following prolonged in vitro coupling to CNT electrodes. We observed gradual remodelling of the inner retina to incorporate CNT assemblies. Electrophysiological recordings demonstrate a progressive increase in coupling between RGCs and the CNT electrodes over three days, characterized by a gradual decrease in stimulation thresholds and increase in cellular recruitment. These results provide novel evidence for time-dependent formation of viable bio-hybrids between CNTs and the retina, demonstrating that CNTs are a promising material for inclusion in retinal prosthetic devices.
Assuntos
Terapia por Estimulação Elétrica/instrumentação , Eletrodos Implantados , Microeletrodos , Nanotubos de Carbono/química , Degeneração Retiniana/fisiopatologia , Degeneração Retiniana/terapia , Próteses Visuais , Potenciais de Ação/fisiologia , Animais , Células Cultivadas , Condutividade Elétrica , Análise de Falha de Equipamento , Teste de Materiais , Camundongos , Nanotubos de Carbono/ultraestrutura , Desenho de Prótese , Propriedades de SuperfícieRESUMO
Chlorogenic acid (CGA) is a polyphenol derivative that widely exists in higher plants like fruits, vegetables, black teas, and some traditional Chinese medicines. In this work, we have proposed a sensitive and selective electrochemical sensor for detection of CGA. The sensor was based on a glassy carbon electrode (GCE) modified with a functional platform by grafting vinyltrimethoxysilane (VTMS) in multi-walled carbon nanotubes (MWCNTs) and covered by a molecularly imprinted siloxane (MIS) film prepared using the sol-gel process. The VTMS was grafted onto the surface of the MWCNTs via in situ free radical polymerization. The MIS was obtained from the acid-catalyzed hydrolysis/condensation of a solution consisting of tetraethoxysilane (TEOS), phenyltriethoxysilane (PTEOS), (3-aminopropyl)trimethoxysilane (APTMS), and CGA as a template molecule. The modification procedure was evaluated by differential pulse voltammetry (DPV) and scanning electron microscopy (SEM). Under optimized operational conditions, a linear response was obtained covering a concentration ranging from 0.08µmolL(-1) to 500µmolL(-1) with a detection limit (LOD) of 0.032µmolL(-1). The proposed sensor was applied to CGA determination in coffee, tomato, and apple samples with recoveries ranging from 99.3% to 108.6%, showing a promising potential application in food samples. Additionally, the imprinted sensor showed a significantly higher affinity for target CGA than the non-imprinted siloxane (NIS) sensor.
Assuntos
Antioxidantes/análise , Ácido Clorogênico/análise , Técnicas Eletroquímicas/métodos , Análise de Alimentos/métodos , Impressão Molecular/métodos , Nanotubos de Carbono/química , Siloxanas/química , Café/química , Limite de Detecção , Solanum lycopersicum/química , Malus/química , Nanotubos de Carbono/ultraestrutura , Transição de FaseRESUMO
Phototherapy, which mainly includes photothermal treatment (PTT) and photodynamic treatment (PDT), is a photo-initiated, noninvasive and effective approach for cancer treatment. The high accumulation of photosensitizers (PSs) in a targeted tumor is still a major challenge for efficient light conversion, to generate reactive oxygen species (ROS) and local hyperthermia. In this study, a simple and efficient hyaluronic acid (HA)-modified nanoplatform (HA-TiO2@MWCNTs) with high tumor-targeting ability, excellent phototherapy efficiency, low light-associated side effects and good water solubility was developed. It could be an effective carrier to load hematoporphyrin monomethyl ether (HMME), owing to the tubular conjugate structure. Apart from this, the as-prepared TiO2@MWCNTs nanocomposites could also be used as PSs for tumor PTT and PDT. Those results in vitro and in vivo showed that the anti-tumor effect of this system-mediated PTT/PDT were significantly better than those of single treatment manner. In addition, this drug delivery system could realize high ratio of drug loading, sustained drug release, prolonged circulation in vivo and active targeted accumulation in tumor. These results suggest that HA-TiO2@MWCNTs/HMME has high potential for tumor synergistic phototherapy as a smart theranostic nanoplatform.
Assuntos
Hematoporfirinas/farmacologia , Nanocompostos/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Sarcoma 180/tratamento farmacológico , Titânio/farmacocinética , Animais , Composição de Medicamentos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Feminino , Hematoporfirinas/sangue , Hematoporfirinas/farmacocinética , Humanos , Hipertermia Induzida/métodos , Injeções Subcutâneas , Lasers , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Terapia de Alvo Molecular/métodos , Nanocompostos/ultraestrutura , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Fármacos Fotossensibilizantes/sangue , Fármacos Fotossensibilizantes/farmacocinética , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/metabolismo , Sarcoma 180/metabolismo , Sarcoma 180/patologia , Nanomedicina Teranóstica/métodos , Titânio/sangueRESUMO
The ultra-short pulse microwave could excite to the strong thermoacoustic (TA) shock wave and deeply penetrate in the biological tissues. Based on this, we developed a novel deep-seated tumor therapy modality with mitochondria-targeting single wall carbon nanotubes (SWNTs) as microwave absorbing agents, which act efficiently to convert ultra-short microwave energy into TA shock wave and selectively destroy the targeted mitochondria, thereby inducing apoptosis in cancer cells. After the treatment of SWNTs (40 µg/mL) and ultra-short microwave (40 Hz, 1 min), 77.5% of cancer cells were killed and the vast majority were caused by apoptosis that initiates from mitochondrial damage. The orthotopic liver cancer mice were established as deep-seated tumor model to investigate the anti-tumor effect of mitochondria-targeting TA therapy. The results suggested that TA therapy could effectively inhibit the tumor growth without any observable side effects, while it was difficult to achieve with photothermal or photoacoustic therapy. These discoveries implied the potential application of TA therapy in deep-seated tumor models and should be further tested for development into a promising therapeutic modality for cancer treatment.
Assuntos
Hipertermia Induzida , Micro-Ondas , Nanotubos de Carbono/química , Neoplasias/terapia , Acústica , Animais , Linhagem Celular Tumoral , Feminino , Hipertermia Induzida/efeitos adversos , Camundongos Endogâmicos BALB C , Mitocôndrias/metabolismo , Nanotubos de Carbono/ultraestrutura , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Fe-filled carbon nanotubes (Fe@CNTs) recently emerged as an effective class of hybrid nanoparticles for biotechnological applications, such as magnetic cell sorting and magnetic fluid hyperthermia. Aiming at studying the effects of both the Fe loading and the magnetocrystalline characteristics in these applications, we describe herein the preparation of Fe@CNTs containing different Fe phases that, upon functionalization with the antibody Cetuximab (Ctxb), allow the targeting of cancer cells. Our experimental findings reveal that an optimal Ctxb/Fe weight ratio of 1.2 is needed for efficient magnetic cell shepherding, whereas enhanced MFH-induced mortality (70 vs. 15%) can be reached with hybrids enriched in the coercive Fe(3)C phase. These results suggest that a synergistic effect between the Ab loading and the Fe distribution in each nanotube exists, for which the maximum shepherding and hyperthermia effects are observed when higher densities of Fe@CNTs featuring the more coercive phase are interfaced with the cells.
Assuntos
Hipertermia Induzida , Ferro/química , Magnetoterapia , Campos Magnéticos , Nanotubos de Carbono/química , Ferro/uso terapêutico , Nanotubos de Carbono/ultraestruturaRESUMO
To enhance the efficacy and optimize the treatment of cancers, the integration of multimodal treatment strategies leading to synergistic effects is a promising approach. The coassembly of multifunctional agents for systematic therapies has received considerable interest in cancer treatment. Herein, Ru(II) complex-functionalized single-walled carbon nanotubes (Ru@SWCNTs) are developed as nanotemplates for bimodal photothermal and two-photon photodynamic therapy (PTT-TPPDT). SWCNTs have the ability to load a great amount of Ru(II) complexes (Ru1 or Ru2) via noncovalent π-π interactions. The loaded Ru(II) complexes are efficiently released by the photothermal effect of irradiation from an 808 nm diode laser (0.25 W/cm(2)). The released Ru(II) complexes produce singlet oxygen species ((1)O2) upon two-photon laser irradiation (808 nm, 0.25 W/cm(2)) and can be used as a two-photon photodynamic therapy (TPPDT) agent. Based on the combination of photothermal therapy and two-photon photodynamic therapy, Ru@SWCNTs have greater anticancer efficacies than either PDT using Ru(II) complexes or PTT using SWCNTs in two-dimensional (2D) cancer cell and three-dimensional (3D) multicellular tumor spheroid (MCTS) models. Furthermore, in vivo tumor ablation is achieved with excellent treatment efficacy under a diode laser (808 nm) irradiation at the power density of 0.25 W/cm(2) for 5 min. This study examines an efficacious bimodal PTT and TPPDT nanoplat form for the development of cancer therapeutics.