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1.
Molecules ; 27(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36234731

RESUMO

Glioma is the most common primary craniocerebral malignant tumor, arising from the canceration of glial cells in the brain and spinal cord. The quality of life and prognosis of patients with this disease are still poor. Doxorubicin (DOX) is one of the most traditional and economical chemotherapeutic drugs for the treatment of glioma, but its toxic effect on normal cells and the resistance of tumor cells to DOX make the application of DOX in the treatment of glioma gradually less effective. To solve this problem, we co-encapsulated DOX and endogenous tumor suppressor miR-125b into nanoparticles (NPs) by nanoprecipitation methods, and passively targeted them into glioma cells. In vitro experiments show that miR-125b and DOX can be effectively encapsulated into nanoparticles with different ratios, and by targeting YES proto-oncogene 1 (YES1), they can affect the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/p53 pathway and induce brain glioma cell apoptosis. They can also affect the DNA damage repair process and inhibit cell proliferation. The obtained data suggest that co-delivery of DOX and miR-125b could achieve synergistic effects on tumor suppression. Nanosystem-based co-delivery of tumor suppressive miRNAs and chemotherapeutic agents may be a promising combined therapeutic strategy for enhanced anti-tumor therapy.


Assuntos
Glioma , MicroRNAs , Nanopartículas , Proteínas Quinases Ativadas por AMP/metabolismo , Adenosina/farmacologia , Monofosfato de Adenosina/farmacologia , Apoptose , Linhagem Celular Tumoral , Dano ao DNA , Doxorrubicina , Glioma/tratamento farmacológico , Glioma/genética , Glioma/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Qualidade de Vida , Proteína Supressora de Tumor p53/genética
2.
J Nanobiotechnology ; 17(1): 23, 2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30711005

RESUMO

BACKGROUND: In recent years, multifunctional theranostic nanoparticles have been fabricated by integrating imaging and therapeutic moieties into one single nano-formulations. However, Complexity of production and safety issues limits their further application. RESULTS: Herein, we demonstrated self-assembled nanoparticles with single structure as a "from one to all" theranostic platform for tumor-targeted dual-modal imaging and programmed photoactive therapy (PPAT). The nanoparticles were successfully developed through self-assembling of hyaluronic acid (HA)-cystamine-cholesterol (HSC) conjugate, in which IR780 was simultaneously incorporated (HSCI NPs). Due to the proper hydrodynamic size and intrinsic targeting ability of HA, the HSCI NPs could accumulate at the tumor site effectively after systemic administration. In the presence of incorporated IR780, in vivo biodistribution and accumulation behaviors of HSCI NPs could be monitored by photoacoustic imaging. After cellular uptake, the HSCI NPs would disintegrate resulting from cystamine reacting with over-expressed GSH. The released IR780 would induce fluorescence "turn-on" conversion, which could be used to image tumor sites effectively. Upon treatment with 808 nm laser irradiation, PPAT could be achieved in which generated reactive oxygen species (ROS) would produce photodynamic therapy (PDT), and subsequently the raised temperature would be beneficial to tumor photothermal therapy (PTT). CONCLUSION: The self-assembled HSCI NPs could act as "from one to all" theranostic platform for high treatment efficiency via PPAT pattern, which could also real-time monitor NPs accumulation by targeted and dual-modal imaging in a non-invasive way.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/química , Nanopartículas/administração & dosagem , Nanopartículas/química , Fotoquimioterapia/métodos , Nanomedicina Teranóstica/métodos , Animais , Linhagem Celular Tumoral , Colesterol/química , Cistamina/química , Feminino , Humanos , Ácido Hialurônico/química , Indóis/química , Camundongos , Camundongos Nus , Nanopartículas/metabolismo , Nanopartículas/ultraestrutura , Técnicas Fotoacústicas , Distribuição Tecidual , Neoplasias de Mama Triplo Negativas/diagnóstico por imagem , Neoplasias de Mama Triplo Negativas/tratamento farmacológico
3.
Appl Opt ; 58(30): 8200-8206, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674490

RESUMO

The speed of optical modulation on a terahertz (THz) pulse is mainly dominated by the optical response of the photocarrier. In order to achieve ultrafast THz modulation, the effective method is to reduce the lifetime of the photocarrier by introducing defects that can trap the photocarriers efficiently. In this paper, we reported the ultrafast optical modulation of THz switching in a 10 nm CdTe nanostructure film. After photoexcitation at 800/400 nm, the THz response of the film is extremely fast with a lifetime of ${\sim}{1.3}\;{\rm ps}$∼1.3ps. Further, the ultrafast transient THz transmission shows almost temperature independence down to 100 K. On the other hand, the transient absorption spectroscopy reveals that the lifetime of photocarriers in CdTe nanostructure film lasts as long as several ns. The 1.3 ps THz photoconductivity response is due to the substantial decrease of photocarrier mobility in a CdTe nanostructure, which comes from the increase of the photocarrier scattering between the photocarrier and the surface states of CdTe nanostructural film. Our experimental results provide a new method to design optically driven ultrafast THz response devices, such as THz switch and THz modulator.

4.
Opt Express ; 25(13): 13944-13952, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28788982

RESUMO

In this article, a novel metamaterial is designed aimed at generating a single electromagnetic hot spot, in order to realize the localization of the incident electromagnetic field at terahertz band, and this kind of metastructure is an ideal candidate for many research fields such as spintronics, nonlinear magnetic response, near-field optics, and optical antenna, etc. The specially tailored metamaterial takes the shape of diabolo with a metal triangle pair connected by a cubic gallium arsenide (GaAs) gap. We demonstrated by simulation that both electric- and magnetic-field of incident THz pulse can be confined in the small GaAs gap when a synchronized femtosecond laser pulse is illuminated. The numerical simulation results show that 2 orders of magnitude of field enhancement can be obtained for a 1-by-1 µm GaAs gap, and the field enhancement factor can also be further improved by tailoring the GaAs gap down to nanometer scale.

5.
Mol Biol Rep ; 40(10): 6019-25, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24057268

RESUMO

The antitumor bioactivities of linobiflavonoid were studied through evaluating its in vitro cytotoxicity against several cell lines (A549, H1975, SMMC-7721, HEP-2 and Vero cells), with the aid of 3-(4,5)-dimethylthiazoly1)-3,5-diphenytetrazolium bromide (MTT) assay. It was found that linobiflavonoid shows more notable inhibiting activity against A549 cells, with IC50 value of 4.67 µM. Furthermore, western blot analysis revealed that linobiflavonoid is able to increase the expression of ß-tubulin, whereas not α-tubulin. In virtuale simulations indicated that linobiflavonoid specifically interacts with the binding pocket which is located at the top of ß-tubulin, due to the presence of strong hydrophobic effects between the core templates and the hydrophobic surface of the tubulin protein (TB) binding site. The binding energy (E inter ) was calculated to be -140.47 kcal/mol. Results above suggest that linobiflavonoid possesses anti-A549 properties relating to ß-tubulin depolymerization inhibition.


Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Biflavonoides/farmacologia , Flavonoides/farmacologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Tubulina (Proteína)/metabolismo , Adenocarcinoma de Pulmão , Biflavonoides/química , Sítios de Ligação , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Flavonoides/química , Humanos , Modelos Moleculares , Polimerização/efeitos dos fármacos , Eletricidade Estática , Termodinâmica , Fatores de Tempo
6.
Zhong Yao Cai ; 36(5): 756-9, 2013 May.
Artigo em Zh | MEDLINE | ID: mdl-24218968

RESUMO

OBJECTIVE: To analyze the chemical composition of essential oil from Thymus citriodorus and its toxic effect on liver cancer cells. METHODS: The essential oil from Thymus citriodorus leaves was extracted by steam distillation, and GC-MS was used for analyzing chemical composition. 35 components were identified which accounted for 95.44% of the total peak area. The main components were borneol (28.82%), thymol (14.43%), 3, 7-dimethyl-1, 6-octadiene-3-ol (8.26%), 1-methyl-4-[alpha-hydroxy-isopropyl] cyclohexene (8.23%) and terpenes camphor (5.1%), et. al. The toxic effects on HepG2 cells and expression of NF-kappabeta65 were measured by MTT assay and confocal laser scanning microscopy, respectively. RESULTS: The IC50 of HepG2 cells inhibition was 0.34%. The mean fluorescence intensity of NF-kappabeta65 expression was as follows: control group 323.25, 2(-10) concentration group 84.18, 2(-11) concentration group 197.93 and 2(-12) concentration group 261.43. CONCLUSION: The essential oil from Thymus citriodorus leaves has strong toxic effects. The induced apoptosis mechanism may be associated with the expression of NF-kappabeta65.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Thymus (Planta)/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Canfanos/análise , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Células Hep G2 , Humanos , Concentração Inibidora 50 , Neoplasias Hepáticas/patologia , NF-kappa B/metabolismo , Óleos Voláteis/isolamento & purificação , Folhas de Planta/química , Timol/análise
7.
Huan Jing Ke Xue ; 44(9): 5275-5287, 2023 Sep 08.
Artigo em Zh | MEDLINE | ID: mdl-37699845

RESUMO

To identify the characteristics and sources of heavy metal pollution in the surrounding soil of a typical pyrite concentrated mining area in Anhui Province, the pH value and the concentrations of Zn, Cu, Cd, Pb, Cr, Ni, Hg, and As in 42 surface soil samples and 16 soil samples from two vertical sections in the study area were collected and measured. The distribution characteristics, pollution assessment, and source analysis of heavy metal elements were conducted using the ArcGis inverse distance weight interpolation method, Nemero comprehensive index method, principal component analysis method, and absolute factor score-multiple linear regression (APCS-MLR) receptor model. The results showed that the average concentration of the eight heavy metals was 1.03-13.14 times the background value in the Tongling area. The local enrichment of Zn, Cu, Cd, Pb, Hg, and As was obvious, and the spatial distribution was basically consistent with the location of man-made mining activities. The single-factor pollution index evaluation showed that Zn, Cu, Cd, Pb, and As had different degrees of pollution risk, and the pollution degree of Cd and Cu was the most serious, accounting for 47.62% and 42.86% of moderate pollution, respectively. The Nemerow comprehensive pollution index evaluation showed that 61.90% of the soil samples in the study area were moderately polluted. The ground accumulation index evaluation showed that the pollution degree of Zn, Cu, Cd, Pb, Hg, and As in the study area was mainly from light pollution to strong pollution. In the vertical soil profile variation, heavy metals were easily enriched in the surface layer of the soil but migrated slowly to the deep layer, with concentrations mainly above 1 m. The results of source analysis showed that the high geological background and mining contribution rates of Zn, Pb, and As were 37.82%, 43.49%, and 46.63%, respectively. The natural contribution rates of weathering of parent material were 34.02%, 40.88%, and 38.52%, respectively. The sources of Cr and Ni were mainly natural sources of weathering of the parent material, with contribution rates of 91.95% and 73.68%, respectively. Geological high background and mining activities contributed 41.91% of the Cu sources, and atmospheric sedimentation and agricultural comprehensive sources contributed 41.30%. There were many sources of Hg. The natural source of weathering of soil parent material contributed 35.60%, geological high background and mining activities contributed 29.87%, and unknown sources contributed 34.05%. The main source of Cd was atmospheric sedimentation and agricultural comprehensive sources, contributing 81.81%.

8.
Nanomaterials (Basel) ; 11(7)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34201941

RESUMO

In this study, a graphene oxide nanoribbons-functionalized carbon nanotubes-graphene oxide (GNFG) complex was hydrothermally synthesized as a nanomaterial for reinforcing cementitious composites, using a modified Hummers' method. Three types of components existed in the GNFG: Type I, the functionalized carbon nanotubes-graphene oxide nanoribbons (FCNTs-GNR); and types II and III are graphene oxide (GO) and functionalized carbon nanotubes (FCNTs), respectively, which exist independently. The dispersivity of GNFG and its effects on the mechanical properties, hydration process, and microstructures of cement pastes were evaluated, and the results were compared with those using cement pastes incorporating other typical carbon nanomaterials. The results demonstrated that dispersion of GNFG in aqueous solutions was superior to that of the CNTs, FCNTs, and GO/FCNTs mixture. Furthermore, the highly-dispersed GNFG (0.05 wt.%) improved the mechanical properties of the cement paste after 28 days of hydration and promoted the hydration of cement compared to CNTs, GO, and GO/FCNTs mixture (0.05 wt.%). The results in this study validated the feasibility of using GNFG with enhanced dispersion as a new nano-reinforcing agent for various cementitious systems.

9.
Sci Rep ; 11(1): 1867, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33479329

RESUMO

In this study, a combination of reverse microemulsion and hydrothermal techniques were used to synthesize HA. A hydrothermal method was used to synthesize HA/TiO2/CNT nanocomposite powders. Cold and hot isostatic pressing techniques were used to fabricate tablet-shaped samples. To investigate the biocompatibility and tribo-mechanical properties of HA/TiO2 and HA/TiO2/CNTs, four samples were prepared with different percentages of CNTs, namely, HA/TiO2 (S0), HA/TiO2/CNT (S1.0), HA/TiO2/CNT (S2.0), and HA/TiO2/CNT (S3.0). The microstructure and morphology of the HA/TiO2/CNTs were characterized by transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Hardness test results show that S3.0 displayed the highest surface hardness (285 HV) compared to other samples. The wear rate of HA/TiO2/CNT with the highest CNT content showed a decrease compared with those of the other samples. The results from nanoindentation tests showed that Young's modulus of the S3.0 sample was 58.1% greater than that of the S0 sample. Furthermore, the human MDA-MB-231 cell line demonstrated good binding to the surface of the samples in the in-vitro biocompatibility evaluation of the HA/TiO2/CNT composites.

10.
Exp Ther Med ; 21(4): 292, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33717235

RESUMO

Glioblastoma is the most common and aggressive type of brain tumor. Although treatments for glioblastoma have been improved recently, patients still suffer from local recurrence in addition to poor prognosis. Previous studies have indicated that the efficacy of chemotherapeutic or bioactive agents is severely compromised by the blood-brain barrier and the inherent drug resistance of glioblastoma. The present study developed a delivery system to improve the efficiency of delivering therapeutic agents into glioblastoma cells. The anticancer drug paclitaxel (PTX) was packed into nanoparticles that were composed of amphiphilic poly (γ-glutamic-acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolaminecopolymer conjugated with targeting moiety transferrin (Tf). The Tf nanoparticles (Tf-NPs) may enter glioblastoma cells via transferrin receptor-mediated endocytosis. MTT assay and flow cytometry were used to explore the cytotoxic effects, cellular uptake and cellular distribution of paclitaxel-loaded nanoparticles. The results indicated that both PTX and PTX-Tf-NPs inhibited the viability of rat glioblastoma C6 cells in a dose-dependent manner, but the PTX-Tf-NPs exhibited a greater inhibitory effect compared with PTX, even at higher concentrations (0.4, 2 and 10 µg/ml). However, both PTX and PTX-Tf-NPs exhibited a reduced inhibitory effect on the viability of mouse hippocampal neuronal HT22 cells compared with that on C6 cells. Additionally, in contrast to PTX alone, PTX-Tf-NPs treatment of C6 cells at lower concentrations (0.0032, 0.0160 and 0.0800 µg/ml) induced increased G2/M arrest, although this difference did not occur at a higher drug concentration (0.4 µg/ml). It was observed that FITC-labeled PTX-Tf-NPs were endocytosed by C6 cells within 4 h. Furthermore, FITC-labeled PTX-Tf-NPs or Tf-NPs co-localized with a lysosomal tracker, Lysotracker Red DND-99. These results of the present study indicated that Tf-NPs enhanced the cytotoxicity of PTX in glioblastoma C6 cells, suggesting that PTX-Tf-NPs should be further explored in animal models of glioblastoma.

11.
Materials (Basel) ; 13(23)2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33260575

RESUMO

Considering the increase in research regarding environmental pollution reduction, the utilization of cementitious material, a commonly used construction material, in photocatalysts has become a desirable research field for the widespread application of photocatalytic degradation technology. Nano-reinforcement technology for cementitious materials has been extensively researched and developed. In this work, as a new and promising reinforcing agent for cementitious materials, the photocatalytic performance of titanium dioxide nanotube (TNT) was investigated. The degradation of methylene blue was used to evaluate the photocatalytic performance of the TNT-reinforced cement paste. In addition, cement paste containing micro-TiO2 (m-TiO2) and nano-TiO2 (n-TiO2) particles were used for comparison. Moreover, the effect of these TiO2-based photocatalytic materials on the cement hydration products was monitored via X-ray diffraction (XRD) and thermogravimetric analysis (TG). The results indicated that all the TiO2 based materials promoted the formation of hydration products. After 28 days of curing, the TNT-reinforced cement paste contained the maximum amount of hydration products (Ca(OH)2). Furthermore, the cement paste containing TNT exhibited better photocatalytic effects than that containing n-TiO2, but worse than that containing m-TiO2.

12.
Nanomaterials (Basel) ; 10(7)2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32630131

RESUMO

In this study, we synthesized binder-free NiCo2O4@NiCo2O4 nanostructured materials on nickel foam (NF) by combined hydrothermal and cyclic voltammetry deposition techniques followed by calcination at 350 °C to attain high-performance supercapacitors. The hierarchical porous NiCo2O4@NiCo2O4 structure, facilitating faster mass transport, exhibited good cycling stability of 83.6% after 5000 cycles and outstanding specific capacitance of 1398.73 F g-1 at the current density of 2 A·g-1, signifying its potential for energy storage applications. A solid-state supercapacitor was fabricated with the NiCo2O4@NiCo2O4 on NF as the positive electrode and the active carbon (AC) was deposited on NF as the negative electrode, delivering a high energy density of 46.46 Wh kg-1 at the power density of 269.77 W kg-1. This outstanding performance was attributed to its layered morphological characteristics. This study explored the potential application of cyclic voltammetry depositions in preparing binder-free NiCo2O4@NiCo2O4 materials with more uniform architecture for energy storage, in contrast to the traditional galvanostatic deposition methods.

13.
Nanomaterials (Basel) ; 9(2)2019 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-30791415

RESUMO

In this study, a series of HZSM-5 catalysts were prepared by the chemical liquid-phase deposition method, and low concentration toluene degradation was carried out in an atmospheric pressure dielectric barrier discharge (DBD) reactor. The catalysts were characterized by X-ray powder diffraction (XRD), SEM, TEM, and N2 adsorption analysis techniques. In addition, several organic contaminants were used to evaluate the adsorption performance of the prepared catalysts, and the effect of pore size on the removal efficiency of toluene and byproduct formation was also investigated. The unmodified HZSM-5 zeolite (Z0) exhibited good performance in toluene removal and CO2 selectivity due to the diffusion resistance of ozone and the amounts of active species (OH• and O•). Meanwhile, the time of flight mass spectrometry (TOF-MS) result showed that there were more byproducts of the benzene ring in the gas phase under the action of small micropore size catalysts. Moreover, the surface byproducts were detected by gas chromatography⁻mass spectrometry (GC-MS).

14.
Zhonghua Nan Ke Xue ; 14(9): 792-5, 2008 Sep.
Artigo em Zh | MEDLINE | ID: mdl-18998461

RESUMO

OBJECTIVE: To investigate the changes of xanthine oxidase (XOD), myeloperoxidase (MPO) and mitochondrial succinate dehydrogenase (SDH) in the testis and the protective effect of ganoderma lucidum spores on the testicular tissue of rats with non-insu- lin-dependent diabetes mellitus (NIDDM). METHODS: Fifty male Wistar rats were divided randomly into a model, a ganoderma and a normal control group, the first two groups injected with 2% STZ (25 mg/kg) through the peritoneum, and the last one with half-and-half sodium citrate/citrate buffer solution. Two weeks after normal diet, glucose tolerance tests were performed and the rats with abnormal glucose tolerance in the model and ganoderma groups received high-fat and high-carbohydrate food, the latter given ganoderma lycium spores (250 mg/kg x d) in addition, both for 10 weeks and all rats fed alone. Glucose tolerance tests were repeated 1 day before the end of the experiment and the testes of the rats were harvested for the determination of XOD, MPO and SDH. RESULTS: SDH was significantly lower (P < 0.05) while XOD and MPO significantly higher in the model group than in the ganoderma and control groups (P < 0.05). The model rats exhibited abnormal convoluted seminiferous tubules, indistinct parietal layers, decreased or abolished gonepoiesis, luminal peripheral fibrous tissue (interstitial substance) accrementition, basal lamina thickening, and vessel wall fibrous tissue accrementition and sclerosis. CONCLUSION: Ganoderma lucidum spores can protect the testis of diabetic rats by reducing free radical-induced damage to the testicular tissue and enhancing the activity of SDH.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Reishi , Testículo/metabolismo , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Peroxidase/metabolismo , Ratos , Ratos Wistar , Esporos Fúngicos , Succinato Desidrogenase/metabolismo , Xantina Oxidase/metabolismo
15.
Zhong Yao Cai ; 31(6): 877-9, 2008 Jun.
Artigo em Zh | MEDLINE | ID: mdl-18998574

RESUMO

OBJECTIVE: To investigate the expression of bcl-2 and bax genes in the liver cancer cell line HepG2 after apoptosis induced by essential oils from Rosmarinus officinalis. METHODS: Essential oils from Rosmarinus officinalis were collected by steam distillation, then its chemical composition was determined by GC-MS. Expression of bcl-2 and bax genes were detected by immunohistochemical method. RESULTS: The liver cancer cell line HepG2 was treated with essential oils from Rosmarinus officinalis at various concentrations for different duration. Expression of bcl-2 gene reduced and expression of bax gene increased in a dose and time dependent manner. CONCLUSION: Essential oils from Rosmarinus officinalis can affect the pattern of bcl-2 and bax genes expressions, and this may increase the apoptosis of liver cancer cell line HepG2.


Assuntos
Apoptose/efeitos dos fármacos , Óleos Voláteis/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Rosmarinus/química , Proteína X Associada a bcl-2/metabolismo , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Folhas de Planta/química , Fatores de Tempo
16.
J Virol Methods ; 139(1): 12-6, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17055591

RESUMO

A capillary zone electrophoresis method was developed for fingerprint determination of allantoic fluid in specific pathogen free (SPF) embryonated chicken eggs. The effects of some crucial parameters, such as buffer type, pH, wavelength and running voltage on the separation were studied systematically. The components of the allantoic fluid were well separated using a fused-silica uncoated capillary with an effective length of 50 cm and an internal diameter of 50 microm. One hundred millimolars sodium tetraborate buffer containing 20 mM sodium dihydrogen phosphate with a final pH 9.8 was used as a running buffer. Comparative fingerprints of allantoic fluid in normal and infected with infectious bronchitis virus (IBV) SPF embryonated chicken eggs were also evaluated. The results showed that there were significant differences between composition of normal allantoic fluid and allantoic fluid infected with IBV, which led to different migration behavior. This method was shown to be stable and reproducible with a relative standard deviation of less than 5% for both migration time and peak current.


Assuntos
Alantoide/química , Líquido Amniótico/química , Eletroforese Capilar/métodos , Animais , Embrião de Galinha/virologia , Concentração de Íons de Hidrogênio , Vírus da Bronquite Infecciosa , Reprodutibilidade dos Testes , Organismos Livres de Patógenos Específicos
17.
Environ Toxicol Pharmacol ; 23(2): 168-73, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21783754

RESUMO

The remedial effects of a plant metallothionein type-2 were observed from lead (Pb) injured rats. BjMT2 from Brassica juncea was expressed in Escherichia coli and purified by affinity chromatography, a purified BjMT2 protein was obtained which strongly reacted with the thiol reagent MBB (monobromobimane). The profiles of erythrocytes, renal tubules and glomerulus of kidney of rats suffered pathological changes from excess Pb were evidently improved by supplying the BjMT2. Quantitative analysis showed that the content of Pb and the amount of leukocytes in blood were significantly declined after supplying BjMT2 to rats. The results indicated that the BjMT2 may have the potential function to decrease Pb toxicification in rate organs and tissues.

18.
Macromol Biosci ; 17(4)2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27762492

RESUMO

Stimuli-responsive nanocarriers with the ability to respond to tumorous heterogeneity have been extensively developed for drug delivery. However, the premature release during blood circulation and insufficient intracellular drug release are still a significant issue. Herein, three disulfide bonds are introduced into the amphiphilic poly(ethylene glycol)-polycaprolactone copolymer blocks to form triple-sensitive cleavable polymeric nanocarrier (tri-PESC NPs) to improve its sensitivity to narrow glutathione (GSH) concentration. The tri-PESC NPs keep intact during blood circulation due to the limited cleaving of triple-disulfide bonds, whereas the loaded drug is efficiently released at tumor cells with the increased concentration of GSH. In vitro studies of doxorubicin-loaded tri-PESC NPs show that the nanocarriers achieve sufficient drug release in cancerous cells and inhibit the tumor cells growth, though they only bring minimum damage to normal cells. Therefore, the tri-PESC NPs with triple-sensitive cleavable bonds hold great promise to improve the therapeutic index in cancer therapy.


Assuntos
Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/química , Nanopartículas/química , Poliésteres/química , Polietilenoglicóis/química , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Doxorrubicina/farmacologia , Endocitose/efeitos dos fármacos , Células HEK293 , Células Hep G2 , Humanos , Espaço Intracelular/metabolismo , Microscopia Confocal , Nanopartículas/ultraestrutura , Oxirredução , Tamanho da Partícula , Poliésteres/síntese química , Polietilenoglicóis/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Eletricidade Estática
19.
J Colloid Interface Sci ; 413: 54-64, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24183430

RESUMO

A novel amphiphilic copolymer (γ-PGA-co-PLA-DPPE) containing poly(γ-glutamic acid) (γ-PGA), polylactide (PLA), and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) segments has been successfully synthesized. The chemical structures of the copolymers were characterized by Fourier-transform infrared spectroscopy (FT-IR), NMR ((1)H NMR, (13)C NMR, (31)P NMR), and thermogravimetric analysis (TGA). In order to estimate the feasibility as novel drug carriers, an anti-tumor model drug, doxorubicin hydrochloride salt (DOX) was encapsulated into the copolymers nanoparticles (NPs) by double emulsion and nanoprecipitation methods. The influence of processing factors on encapsulation efficiency and particle size using double emulsion and nanoprecipitation technique were studied. In addition, the DOX-loaded NPs exhibited pH-dependent drug release profiles in vitro. The cumulative release of DOX-loaded NPs was much faster at pH 5.0 than that at pH 7.4. In vitro cytotoxicity test of DOX-loaded NPs against Hela and C666-1 cells demonstrated that DOX-loaded NPs exhibited effectively time-delayed cytotoxicity. Confocal laser scanning microscopy (CLSM) showed that DOX-loaded NPs accumulated mostly in lysosomes instead of cell nucleus, in contrast to free DOX. Therefore, the copolymer nanoparticles were proved to be an available carrier for anti-tumor drug delivery.


Assuntos
Portadores de Fármacos , Nanopartículas , Fosfatidiletanolaminas/química , Ácido Poliglutâmico/análogos & derivados , Linhagem Celular , Doxorrubicina/administração & dosagem , Humanos , Microscopia Eletrônica de Transmissão , Fosfatidiletanolaminas/administração & dosagem , Ácido Poliglutâmico/administração & dosagem , Ácido Poliglutâmico/química , Termogravimetria
20.
Colloids Surf B Biointerfaces ; 123: 787-96, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25454663

RESUMO

Targeted drug delivery strategies have shown great potential in solving some problems of chemotherapy, such as non-selectivity and severe side effects, thus enhancing the anti-tumor efficiency of chemotherapeutic agents. In this work, we have prepared a novel nanoparticle consisted of amphiphilic poly(γ-glutamic acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolamine (γ-PGA-MAL-PLA-DPPE) copolymer decorated with transferrin (Tf), which can specifically deliver anti-cancer drug paclitaxel (PTX) to the tumor cells for targeting chemotherapy. These nanoparticles (NPs) have preferable particle size, high encapsulation efficiency and a pH-dependent release profile. As expected, The Tf modification mediate specific targeting to nasopharyngeal carcinoma (C666-1) cells and human cervical carcinoma (Hela) cells with the transferrin receptor (TfR) overexpressed and enhance cellular uptake of the NPs, as demonstrated by flow cytometry and confocal microscopy assays. In vitro cytotoxicity studies reveal that the NPs have excellent biocompatibility, and the presence of Tf enhance the activity of PTX to the targeted cells. All these results prove that Tf modified γ-PGA-MAL-PLA-DPPE NPs could facilitate the tumor-specific therapy. Therefore, such a targeting drug delivery system provides significant advances toward cancer therapy.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Ácido Poliglutâmico/análogos & derivados , Polímeros/química , Transferrina/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Portadores de Fármacos/química , Humanos , Paclitaxel/administração & dosagem , Paclitaxel/química , Fosfatidiletanolaminas , Ácido Poliglutâmico/química
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