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oe1(光电查) - 科学论文

285 条数据
?? 中文(中国)
  • PEGylated doxorubicin cloaked nano-graphene oxide for dual-responsive photochemical therapy

    摘要: Graphene oxide (GO) own huge surface area and high drug loading capacity for aromatic molecules, such as doxorubicin (DOX). However, its biocompatibility is poor and it might agglomerate in physiological condition. Chemical modification of GO with hydrophilic polymer, especially PEGylation, was a common method to improve its biocompatibility. But the chemical modification of GO was complicated, and its drug loading capacity might be reduced because of the occupation of its functional groups. In this study, DOX-PEG polymers with different PEG molecular weight were synthesized to modify nano graphene oxide (NGO) to simultaneously realize the solubilization of NGO and the high loading capacity of DOX. The result showed that the drug release of NGO@DOX-PEG was pH sensitive. NIR irradiation could augment the drug release, cellular uptake, cytotoxicity and nuclear translocation of nanodrugs. Among the three kinds of nanodrugs, NGO@DOX-PEG5K was superior to others. It suggested that after conjugating with PEG, the bond between DOX-PEG and NGO was weakened, which resulted in a better drug release and treatment effect. In summary, the NIR and pH dual-responsive NGO@DOX-PEG nanodrugs were developed by noncovalent modification, and it demonstrated excellent biocompatibility and photochemical therapeutic effect, presenting a promising candidate for antitumor therapy, especially NGO@DOX-PEG5K.

    关键词: Nano-drug Delivery System,pH sensitive,Nano-Graphene Oxide,photochemical therapy,Doxorubicin

    更新于2025-09-23 15:23:52

  • Characterization of M1 and M2 polarization phenotypes in peritoneal macrophages after treatment with graphene oxide nanosheets

    摘要: Macrophages play a key role in nanoparticle removal and are primarily responsible for their uptake and trafficking in vivo. Due to their functional plasticity, macrophages display a spectrum of phenotypes between two extremes identified as pro-inflammatory M1 and reparative M2 macrophages, characterized by the expression of specific cell surface markers and the secretion of different cytokines. The influence of graphene oxide (GO) nanosheets functionalized with poly(ethylene glycol-amine) and labelled with fluorescein isothiocyanate (FITC-PEG-GO) on polarization of murine peritoneal macrophages towards M1 and M2 phenotypes was evaluated in basal and stimulated conditions by flow cytometry and confocal microscopy through the expression of different cell markers: CD80 and iNOS as M1 markers, and CD206 and CD163 as M2 markers. Although FITC-PEG-GO did not induce M1 or M2 macrophage polarization after 24 and 48 h in basal conditions, this nanomaterial decreased the percentage of M2 reparative macrophages. We have also compared control macrophages with macrophages that have or have not taken up FITC-PEG-GO after treatment with these nanosheets (GO+ and GO- cells, respectively). The CD80 expression diminished in GO+ macrophages after 48 h of GO treatment but the CD206 expression in GO+ population showed higher values than in both GO- population and control macrophages. In the presence of pro-inflammatory stimuli (LPS and IFN-γ), a significant decrease of CD80+ cells was observed after treatment with GO. This nanomaterial also induced significant decreases of CD206+ and CD163+ cells in the presence of reparative stimulus (IL-4). The CD80, iNOS and CD206 expression was lower in both GO- and GO+ cells than in control macrophages. However, higher CD163 expression was obtained in both GO- and GO+ cells in comparison with control macrophages. All these facts suggest that FITC-PEG-GO uptake did not induce the macrophage polarization towards the M1 pro-inflammatory phenotype, promoting the control of the M1/M2 balance with a slight shift towards M2 reparative phenotype involved in tissue repair, ensuring an appropriate immune response to these nanosheets.

    关键词: Graphene oxide nanosheets,Macrophage polarization,Peritoneal macrophages,Cytokine profiling

    更新于2025-09-23 15:23:52

  • Nanoscale reduced graphene oxide-mediated photothermal therapy together with IDO inhibition and PD-L1 blockade synergistically promote antitumor immunity

    摘要: Despite the potential efficacy of immune checkpoint blockade for effective treatment of cancer, this therapeutic modality is not generally curative and only a fraction of patients respond. Combination approaches provide strategies to target multiple antitumor immune pathways to induce synergistic antitumor immunity. Here, a multi-combination immunotherapy including photothermal therapy (PTT), indoleamine-2,3-dioxygenase (IDO) inhibition and programmed cell death-ligand 1 (PD-L1) blockade is introduced for inducing synergistic antitumor immunity. We designed a multifunctional IDO inhibitor (IDOi)-loaded reduced graphene oxide (rGO)-based nanosheets (IDOi/rGO nanosheets) with the properties to directly kill tumor cells under laser irradiation and in situ trigger antitumor immune response. In vivo experiments further revealed that the triggered immune response can be synergistically promoted by IDO inhibition and PD-L1 blockade; the responses included the enhancement of tumor-infiltrating lymphocytes (TILs) including CD45+ leukocytes, CD4+ T cells, CD8+ T cells and NK cells, the inhibition of the immune suppression activity of regulator T cells (Tregs) and the production of INF-γ. We also demonstrate that the three combinations of PTT, IDO inhibition and PD-L1 blockade could effectively inhibit the growth of both irradiated tumors and tumors in distant sites without PTT treatment. This work can be thought as an important proof-of-concept to target multiple antitumor immune pathways to induce synergistic antitumor immunity.

    关键词: photothermal therapy,reduced graphene oxide,IDO inhibition,combinatorial immunotherapy,PD-L1

    更新于2025-09-23 15:23:52

  • Synthesis of N-CuMe2Pc nanorods/graphene oxide nanocomposite for symmetric supercapacitor electrode with excellent cyclic stability

    摘要: Recent progress in the construction of non-peripheral octamethyl-substituted copper(II) phthalocyanine (N-CuMe2Pc) has opened up new strategies for energy storage applications. Since metal phthalocyanines can deliver excellent redox activities, we have prepared composite based on different ratios of N-CuMe2Pc and graphene oxide (GO) through a simple ultrasound process and evaluated their electrochemical performance for supercapacitor applications. As-prepared composites exhibit superior electrochemical activities as the results of the synergistic effect. A maximum specific capacitance of 291.6 F g?1 is achieved for the G10P2 electrode (Graphene oxide 10 mg and N-CuMe2Pc 2 mg) at 0.5 A g?1 which two times higher than their individual components. Further, the fabricated symmetric device shows that the excellent cyclic stability of about 100.1% over 5000 cycles. The experimental findings ensure the potential application of copper-phthalocyanine/GO composite as an electrode material for the next-generation supercapacitor applications.

    关键词: Nanocomposite,Specific capacitance,Cyclic stability,Graphene oxide,Phthalocyanine

    更新于2025-09-23 15:23:52

  • Graphene oxide-quenching-based fluorescence in situ hybridization (G-FISH) to detect RNA in tissue: Simple and fast tissue RNA diagnostics

    摘要: FISH-based RNA detection in paraffin-embedded tissue can be challenging, with complicated procedures producing uncertain results and poor image quality. Here, we developed a robust RNA detection method based on graphene oxide (GO) quenching and recovery of fluorescence in situ hybridization (G-FISH) in formalin-fixed paraffin-embedded (FFPE) tissues. Using a fluorophore-labeled peptide nucleic acid (PNA) attached to GO, the endogenous long noncoding RNA BC1, the constitutive protein β-actin mRNA, and miR-124a and miR-21 could be detected in the cytoplasm of a normal mouse brain, primary cultured hippocampal neurons, an Alzheimer’s disease model mouse brain, and glioblastoma multiforme tumor tissues, respectively. Coding and non-coding RNAs, either long or short, could be detected in deparaffinized FFPE or frozen tissues, as well as in clear lipid-exchanged anatomically rigid imaging/immunostaining-compatible tissue hydrogel (CLARITY)-transparent brain tissues. The fluorescence recovered by G-FISH correlated highly with the amount of miR-21, as measured by quantitative real time RT-PCR. We propose G-FISH as a simple, fast, inexpensive, and sensitive method for RNA detection, with a very low background, which could be applied to a variety of research or diagnostic purposes.

    关键词: glioblastoma multiforme tumor,tissue RNA diagnostics,Graphene oxide-quenching-based fluorescence in situ hybridization (G-FISH),Alzheimer’s disease,formalin-fixed paraffin-embedded (FFPE) tissue

    更新于2025-09-23 15:23:52

  • In-Situ covalent synthesis of gold nanorods on GO surface as ultrasensitive Raman probe

    摘要: In this paper, using thiolated graphene oxide (GO‐O‐SH) as substrate, gold nanorods (AuNRs) covalently linked to the GO surface by in‐situ seed growth method were first reported. The as‐prepared composites were characterized by UV–vis spectrum, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT‐IR). Experimental results indicated that the introduction of short flexible organic chain between GO and AuNRs contributed to the homogenous synthesis of gold rods, and uniform gold nanorods with aspect ratio within 3~8 were covalently linked to the surface of GO with high stability and yield. The strategy represented an outstanding improvement in comparison to the traditional route for fabricating the two GO@AuNRs composites. Furthermore, based on coupling of nanomaterials, the composites could act as high sensitive Raman probe with limit of detection (LOD) reaching 1 × 10?12 M.

    关键词: covalent synthesis,Raman probe,graphene oxide (GO),gold nanorods

    更新于2025-09-23 15:23:52

  • UV Illumination-Enhanced Molecular Ammonia Detection Based On a Ternary-Reduced Graphene Oxide–Titanium Dioxide–Au Composite Film at Room Temperature

    摘要: In this work, we report on UV illumination enhanced room-temperature trace NH3 detection based on ternary composites of reduced graphene oxide nanosheets (rGO), titanium dioxide nanoparticles (TiO2) and Au nanoparticles as the sensing layer, which is firstly reported by far. The effect of UV state as well as componential combination and content on the sensing behavior disclosed that, rGO nanosheets served as not only a template to attach TiO2 and Au, but an effective electron collector and transporter; TiO2 nanoparticles acted as a dual UV and NH3 sensitive material; Au nanoparticles could increase the sorption sites and promote charge separation of photoinduced electron-hole pairs. The as-prepared rGO/TiO2/Au sensors were endowed with a sensing response of 8.9% toward 2 ppm NH3, a sensitivity of 1.43×10-2/ppm within the investigated range, nice selectivity, robust operation repeatability and stability, which was fairly competitive in comparison with previous work. Meanwhile, the experimental results provided clear evidence of inspiring UV-enhanced gas detection catering for the future demand of low power-consumption and high sensitivity.

    关键词: Room temperature.,Gas sensor,Reduce graphene oxide,Ammonia,Au nanoparticle,Titanium dioxide,UV illumination

    更新于2025-09-23 15:23:52

  • Optical properties of amine-functionalized graphene oxide

    摘要: Important applications of graphene oxide (GO) its derivatives have been found in several areas: energy materials, water treatment, environmental, catalytic, photocatalytic, and biomedical technologies. Among them, the application of GO in optical biosensors has attracted ever-increasing interest in the past few years. In the present work, GO was amine-functionalized by a solvent-free one-step method with two aromatic amines: 1-aminopyrene (AP), and 2-aminofluorene (AF); and one aliphatic amine 1-octadecylamine (ODA). Particle size was estimated by field emission-scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Optical properties have been evaluated by application of photoluminescence (PL), FTIR, UV–VIS, and Raman spectroscopy. As a result, this study offers an efficient way to tune the optical properties due to their amine functionalization, favoring the development of optoelectronic and biological applications using graphene-based materials in the future.

    关键词: Amine functionalization,Optical properties,Sensors,Graphene oxide

    更新于2025-09-23 15:23:52

  • Optimizing P25-rGO composites for pesticides degradation: Elucidation of photo-mechanism

    摘要: The junction of graphene oxide with TiO2 particles can help develop more efficient photocatalysts capable to harvest radiation in a wider range of the electromagnetic spectrum for real photocatalytic applications. The synthesis procedure of TiO2 P25-rGO composites was optimized to photodegrade a selected mixture of pesticides classified by EU as priority pollutants (alachlor, diuron, atrazine and isoproturon). The influence of temperature and time of hydrothermal method, as well as the effect of graphene oxide (GO) percentage added in the synthesis, was studied to obtain the nanocomposite that showed the highest photoactivity. Long time and moderate temperature have offered the best interaction between TiO2 P25 and rGO. GO was quantitatively reduced to rGO during the hydrothermal treatment, but maintains a higher level of disorder. The optimal GO loading was found around 0.25 wt. %, which allowed the photocatalyst achieve high photocatalytic performance both in phenol and pesticides photodegradation. Finally, in order to try to elucidate the photocatalytic mechanism of the selected mixture of pesticides three scavengers were employed: methanol to scavenge hydroxyl radicals, formic acid for the photogenerated holes, and copper (II) nitrate to quench the electrons of the conduction band. In conclusion, all these pesticides were mostly photodegraded by the hydroxyl radicals (HO?) produced from the photo-induced holes (h+); given that the oxidant species generated from electrons or mediated by direct mechanism were not relevant.

    关键词: Scavengers,TiO2P25-reduced graphene oxide composites,Pesticides,Photo-mechanism

    更新于2025-09-23 15:23:52

  • Mitigating the electromagnetic radiation by coupling use of waste cathode-ray tube glass and graphene oxide on cement composites

    摘要: With technological development, the rapid growing numbers of electronic devices generate severe electromagnetic interference (EMI) and radiation to human environment. In this study, the coupling effect of graphene oxide (GO) addition (up to 0.10 wt.% of cement) and waste cathode-ray tube (CRT) glass replacement for fine aggregates (30 and 60 wt.%) in cement-based composites on mitigating EMI was studied. The electric permittivity obtained using a decoupling method was applied for evaluating the EMI shielding capacity of cement-based composites, while direct current (DC) electrical resistance measurement is conducted using four-probe method. The DC electrical resistivity of specimens increases insignificantly with increasing in GO content, but remarkably with increasing CRT glass content from 30 to 60 wt.%. The 60 wt.% replacement of waste CRT glass with 0.1 wt.% GO addition increases the relative permittivity by about 50% and 200% when the frequency is in the ranges of 104–5 × 106 Hz and 101–103 Hz, respectively. It is concluded that a significant increase in the permittivity can be obtained owing to the synergetic interaction between waste CRT glass and GO. The improvement in the EMI shielding ability of cement-based composites not only enables the applications of these composites in mitigating electromagnetic pollution, but also promotes large-volume recycling of toxic waste CRT glass.

    关键词: Permittivity,Waste CRT glass,Cement composite,Graphene oxide,Electromagnetic interference

    更新于2025-09-23 15:23:52