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Biothiol detection by “ON-OFF-ON” fluorescence probe based on anthracene derivative
摘要： Two thiols fluorescent probes of copper complex based on anthracene derivative was designed. Two compounds (1 and 2) were obtained by the reaction of 9-furaldehyde with benzenesulfonamide and p-nitrobenzenesulfonamide. Then, these compounds were combined with copper ion and two copper complexes (compound 1-Cu2+ and compound 2-Cu2+) formed. Due to the paramagnetic effect of copper caused fluorescence quenching, two compounds showed strong fluorescence while compound-Cu2+ almost had no fluorescence. With the additions of cysteine (Cys) and glutathione (GSH), the fluorescence intensities recovered again. While the additions of other amino acids almost did not induce any change. UV-Vis, fluorescence spectra and Circular Dichroism suggested that two copper complexes showed better selectivity and sensitivity to small molecule biothiols among amino acids tested. In addition, cytotoxicity experiments showed that two fluorescence probes have potential application value for biological thiols detection in live cells.
关键词： Cytotoxicity experiment,Fluorescent probe,Biological thiols,Circular dichroism,9-furaldehyde
更新于2025-09-09 09:28:46
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Irradiation Effects on Polymer-Grafted Gold Nanoparticles for Cancer Therapy
摘要： In the context of cancer treatment, gold nanoparticles (AuNPs) are considered as very promising radiosensitizers. Here, well-defined polymer-grafted AuNPs were synthesized and studied under gamma irradiation to better understand the involved radiosensitizing mechanisms. First, various water-soluble and well-defined thiol-functionalized homopolymers and copolymers were obtained through Atom Transfer Radical Polymerization. They were then used as ligands in the one-step synthesis of AuNPs, resulting in stable hybrid metal-polymer nanoparticles. Second, these nano-objects were irradiated in solution by gamma rays at different doses. Structures were fully characterized through SEC, SAXS and SANS measurements, prior and after irradiation. We were thus able to quantify and to localize radiation impacts onto the grafted polymers, revealing the production sites of reactive species around AuNPs. Both external and near-surface scissions were observed. Interestingly, the ratio between these two effects was found to vary according to the nature of polymer ligands. Medium-range and long-distance dose enhancements could not be identified from the calculated scission yields, but several mechanisms were considered to explain high yields found for near-surface scissions. Then, cytotoxicity was shown to be equivalent for both non-irradiated and irradiated polymer-grafted NPs, suggesting that released polymer fragments were non-toxic. Finally, the potential to add bioactive molecules such as anticancer drugs has been explored by grafting doxorubicin (DOX) onto the polymer corona. This may lead to nano-objects combining both radiosensitization and chemotherapy effects. This work is the first one to study in details the impact of radiation on radiosensitizing nano-objects combining physical, chemical and biological analyses.
关键词： irradiation,Polymer-grafted AuNPs,radiosensitization,doxorubicin,cytotoxicity,SAXS,SANS
更新于2025-09-09 09:28:46
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Fluorescent boron Schiff bases dyes for staining silk fibroin: Green synthesis, structural characterization, DFT, and photophysical properties
摘要： Five novel organoboron complexes were synthesized in just 15 min via microware irradiation, by one pot multicomponent reactions between diverse aryl aldehydes with benzoylhydrazide, or 4‐nitrobenzoylhidrazine and diphenyl boronic acid, in a 1:1:1 ratio in benzene. The products were characterized by 1H, 13C, 11B NMR, UV, IR, spectroscopy and high‐resolution mass spectrometry (HRMS). The molecular structure was also determined by single‐crystal X‐ray diffraction for two complexes, which showed the tetra‐coordination of the boron atoms giving rise to distorted tetrahedral molecular geometry with a strong intermolecular C‐H···π interactions. In spite of the low quantum yields exhibited by the series in solution, some complexes stained uniformly the silk fibroins emitting enough fluorescence to allow its characterization by confocal microscopy. Boron as chelate center of the five complexes resulted not to be toxic for B16F10 cells, these compounds are appropriate for their used in medical applications.
关键词： organoboron,silk fibroin,cytotoxicity,confocal microscopy,fluorescent
更新于2025-09-09 09:28:46
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ZnO nanoparticles modified with an amphipathic peptide show improved photoprotection in skin
摘要： ZnO nanoparticles of different sizes were functionalized with an amphipathic peptide and its effect on nanoparticle stabilization and UV photoprotective activity was studied in this article. The peptide modified nanoparticles exhibited lower aggregation, significant reduction in Zn2+ leaching in-vitro and even inside the cells for smaller particle sizes, reduced photocatalytic activity and reduced cellular toxicity under UV-B treated conditions. In addition, the peptide modified 60 nm sized ZnO nanoparticles showed lower genotoxicity, lower oxidative stress induction levels, less DNA damage responses and less immunogenic potential than the bare counterparts in presence of UV-B rays. They localized more in the stratum corneum and epidermis ex-vivo indicating better retention in epidermis and demonstrated improved UV-B protection and/or skin integrity in SKH-1 mice in-vivo as compared to unmodified nanoparticles and commercial UV protective agents tested. To our knowledge, this is the first report on application of peptide modified ZnO nanoparticles for improved photoprotection.
关键词： UV-B rays,ZnO nanoparticles,cytotoxicity,cell penetrating peptide,photoprotection
更新于2025-09-09 09:28:46
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Systematic Toxicity Evaluations of High-Performance Carbon “Quantum” Dots
摘要： Carbon dots (CDots) in a general structure of small carbon nanoparticles with various surface passivation schemes have emerged to represent a new class of carbon nanomaterials in now a rapidly advancing and expanding research field. Among various synthesis methods, the use of pre-processed and selected small carbon nanoparticles for deliberate chemical functionalization of the particle surface with organic molecules have produced high-performance and structurally better defined CDots. Specifically, small organic molecules 2,2'-(ethylenedioxy)bis(ethylamine) and 3-ethoxypropylamine were used for the effective surface passivation of the carbon nanoparticles via chemical functionalization to yield CDots that are brightly fluorescent and also structurally ultra-compact, amenable to various desired cell imaging applications. Thus, a systematic evaluation of these CDots on their cytotoxicity profiles is necessary, and performed in this study by using a diverse selection of cell lines. Also for fluorescence imaging, CDots were modified with their encapsulating selected organic dyes for much enhanced red/near-IR fluorescence emissions. These modified CDots with the dyes as guest were also evaluated for their cytotoxicity profiles. The results suggest that the CDots without and with the guest dyes are generally nontoxic to the selected cell lines, further supporting the notion that CDots can be used as high-performance yet nontoxic bioimaging agents.
关键词： Carbon Dots,Cytotoxicity,Host-Guest
更新于2025-09-04 15:30:14
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Specific Targeting of Breast Cancer Cells with Antibodies Conjugated Gold Nanoparticles
摘要： Background and Objective: Gold nanoparticles (AuNP) conjugated with either EpCAM or TARP antibodies and an anticancer agent, paclitaxel (PTX), for tumour targeting and therapy were synthesised using a simple chemistry. Methods: The AuNP surface was functionalised using a two-step modification approach. The conjugates were characterised using Transmission Electron Microscopy (TEM) and infrared spectroscopy. Results: The cytotoxicity assay of T47D cells treated with only antibodies conjugated to the gold nanoparticles did not show any cytotoxicity to the cells, which indicates these nanoconjugates are suitable for intracellular delivery of anticancer drugs. Conclusion: When using AuNPs with antibodies and the cancer chemotherapy agent PTX attached simultaneously to the functionalised AuNPs, the reduction of cell viability was significantly higher compared to PTX-thiol-AuNPs conjugate system where no antibodies were used.
关键词： drug delivery,antibodies,paclitaxel,EpCAM,Gold nanoparticles,TARP,cytotoxicity
更新于2025-09-04 15:30:14
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Synthesis, Photothermal Effect and Cytotoxicity of Fe <sub/>3</sub> O <sub/>4</sub> @Au Nanocomposites
摘要： It is currently a very active research area to develop multifunctional nanocomposites (NCs) which integrate the novel properties from various nanomaterials for multimodal imaging and simultaneous therapy. These theranostic nanoplatforms can provide complementary information from each imaging modality for accurate diagnosis and, at the same time, afford an imaging-guided focused tumor therapy. Among them, core/shell Fe3O4@Au NCs have attracted wide attention due to their unique advantages in magnetic targeting, multimodal imaging and photothermal therapy. This study developed a layer-by-layer assembling approach to synthesize Fe3O4@Au NCs with high photothermal conversion efficiency. The as-synthesized NCs showed significant photothermal ablation capability to HeLa cells in vitro under near infrared laser irradiation. To ensure the safety for medical applications, the bio-effects of Fe3O4@Au NCs on RAW264.7 cells were carefully assessed, in terms of cell viability, oxidative stress and apoptosis. We have demonstrated that Fe3O4@Au NCs had good biocompatibility in RAW264.7 cells and no significant cytotoxicity was found. Therefore, the Fe3O4@Au NCs synthesized in this study have great potential as an ideal candidate for CT/MR imaging and photothermal therapy.
关键词： RAW264.7 Cells,HeLa Cells,Fe3O4@Au Nanocomposites,Cytotoxicity,Photothermal Therapy
更新于2025-09-04 15:30:14
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One-Step Synthesis of Fluorescent Carbon Dots for Bio-Labeling Assay
摘要： Luminescent carbon dots, a newcomer in the domain of nanolights and nanomaterials have been studied extensively since past few years due to their fascinating properties of sensor design, biocompatibility, cell tracking, or fluorescence based live cell assays, medical diagnosis, photocatalysts, and also being potential building blocks for nanodevices. In this study, one-pot green synthesis of water dispersible fluorescent carbon dots have been synthesized by using roasted gram shells. The structural and optical properties of the as-prepared carbon dots are characterized by TEM, FTIR, UV-vis absorption, photoluminescence spectra. The carbon dots showed greenish blue fluorescence under UV irradiation, excitation dependent emission, upconverted emission, high pH tolerance, and good biocompatibility. The carbon dots labeled Escherichia coli (E. coli) unveiled multicolor emission behavior under different excitation wavelength. These carbon dots showed their superiority with respect to commercially available synthetic dyes which have severe limitations including photobleaching effect, high cost, etc. The incorporation of carbon dots in the bacterial culture medium does not show any kind of growth delay of the bacterium up to 400 mg mL?1. The goal is to establish this carbon dots in bio-labeling assay with its physicochemical features (small particle size, high luminescence efficiency, good biocompatibility, low toxicity) against various environments such as wide range of pH, high ionic medium. Concisely, this work bestows an innovative aspect to the commercialization of carbon dots as a potent alternative to synthetic organic dyes for multicolor emitting probes for cell-labeling gram negative bacteria E. coli.
关键词： carbon dots,E. coli,bio-labeling,cytotoxicity,fluorescence
更新于2025-09-04 15:30:14
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Facile Synthesis and Controllable Emission of Tm <sup>3+</sup> /Er <sup>3+</sup> -Doped and -Co-doped α-NaYbF <sub/>4</sub> Upconversion Nanocrystals
摘要： Tm3+, Er3+-doped and -co-doped α-NaYbF4 nanoparticles were synthesized via a facile hydrothermal route with oleic acid as the capping agent. Experimental results showed that the doped NaYbF4 nanoparticles possessed a cubic phase with the average size of ～13 nm. Upon excitation by a 980 nm laser, the as-synthesized nanoparticles exhibited blue and red upconversion emissions corresponding to the monodoped Tm3+, Er3+ in the cubic-phase NaYbF4, respectively, and intense green and red emissions in the Tm3+/Er3+-co-doped NaYbF4 nanoparticles. Furthermore, the possible energy transfer mechanism among Yb3+/Tm3+/Er3+ in α-NaYbF4 nanoparticles was also proposed. The cell toxicity test revealed that the as-synthesized upconversion nanoparticles possessed remarkably low cytotoxicity. All of the advantageous features including facile synthesis, controllable emission, and low cytotoxicity make the upconversion nanoparticles promising for multicolor bioimaging and anti-counterfeiting applications.
关键词： anti-counterfeiting applications,multicolor bioimaging,upconversion nanocrystals,hydrothermal synthesis,energy transfer mechanism,α-NaYbF4,low cytotoxicity,Tm3+/Er3+-doped
更新于2025-09-04 15:30:14
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Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications
摘要： In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be ?15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.
关键词： antibacterial,silver,Durio zibethinus seed,green synthesis,cytotoxicity,nanoparticles
更新于2025-09-04 15:30:14