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oe1(光电查) - 科学论文

13 条数据
?? 中文(中国)
  • Polydopamine-Based Tumor-Targeted Multifunctional Reagents for Computer Tomography/Fluorescence Dual-Mode Bioimaging-Guided Photothermal Therapy

    摘要: Development of multifunctional diagnosis and treatment reagents is very meaningful in clinical application. Herein, we developed a polydopamine-based (PDA-based) tumor targeted multifunctional reagent by surface-initiated atom transfer radical polymerization (ATRP) strategy. First, the targeted PDA nanoparticles were prepared via combining with folic acid (FA) and dopamine. Then ATRP technology was used to graft the europium(III) complexes onto PDA surface (defined as FEDA). A series of detections revealed that the FEDA nanoparticles had been successfully prepared and exhibited a bright X-ray computer tomography (CT) and photoluminescence (PL) dual-mode imaging efficiency and an excellent photothermal therapy (PTT) effect in vivo/in vitro.

    关键词: europium(III) complexes,polydopamine,dual-mode imaging-guided photothermal therapy,folic acid targeted,atom transfer radical polymerization

    更新于2025-09-23 15:23:52

  • Functionalized fluorescent carbon nanoparticles for sensitively targeted of folate-receptor-positive cancer cells

    摘要: The folic acid-functionalized fluorescent carbon dots (FA-CDs) was synthesized via the assembly of FA to the surface of CDs. A facile hydrothermal method with proline and ethylenediamine as precursors was used to fabricate CDs. The as-prepared CDs possessed active amino groups where the CDs could be further engineered for the conjugation with FA. The uptake of the as-synthesized FA-CDs by FR positive MCF-7 cells (FR++) and HepG-2 cells (FR+) via receptor-mediated endocytosis was demonstrated by confocal laser scanning microscopy, which is further verified by a comparative study with FR-negative PC-12 cells (FR-). The bright fluorescence can be observed in FR positive MCF-7 cells while negligible fluorescence was observed in PC-12 cells with low-expressed FR, demonstrating that FA-CDs could accurately identify FR-positive cancer cells from normal cells. The FA-CDs shared favorable biocompatibility, excellent optical properties and ultra-low toxicity etc. Holding these superior properties, the FA-CDs was implemented as a highly effective platform for biological labeling and imaging, which may provide a innovative vision for cancer diagnosis and succeeding personalized therapy.

    关键词: Folic acid-functionalized,Targeted bioimaging,Cancer cells,Carbon dots

    更新于2025-09-23 15:22:29

  • Alteration of lens and retina textures from mice embryos with folic acid deficiency: image processing analysis

    摘要: Purpose Folic acid (FA) is an essential vitamin for embryonic development. It plays particularly a critical role in RNA, DNA and protein synthesis. On the other hand, the collagen IV and laminin-1 are important proteins during embryonic development. This study was done to find if FA deficiency at a short and a long term in mothers could alter the tissue texture of retina and lens of the progeny. Methods Collagen IVand laminin-1 were localized by immunohistochemistry in the lens and retina of the FA-deficient embryos. To carry out the image processing, texture segmentation was performed through canny edge detection and Fourier transform (FT). We defined a parameter, the grain size, to describe the texture of the lens and retina. A bootstrap method to estimate the distribution and confidence intervals of the mean, standard deviation, skewness and kurtosis of the grain size has been developed. Results Analysis through image processing using Matlab showed changes in the grain size between control- and FA-deficient groups in both studied molecules. Measures of texture based on FT exhibited changes in the directionality and arrangements of type IV collagen and laminin-1. Conclusions Changes introduced by FA deficiency were visible in the short term (2 weeks) and evident in the long term (8 weeks) in both grain size and orientation of fibre structures in the tissues analysed (lens and retina). This is the first work devoted to study the effect of FA deficit in the texture of eye tissues using image processing techniques.

    关键词: Matlab texture analysis,Laminin-1,Lens,Type IV collagen,Folic acid deficiency,Retina

    更新于2025-09-23 15:21:01

  • Dual-emission CdTe/AgInS2 photoluminescence probe coupled to neural network data processing for the simultaneous determination of folic acid and iron (II)

    摘要: This work focused on the combination of CdTe and AgInS2 quantum dots in a dual-emission nanoprobe for the simultaneous determination of folic acid and Fe(II) in pharmaceutical formulations. The surface chemistry of the used QDs was amended with suitable capping ligands to obtain appropriate reactivity in terms of selectivity and sensitivity towards the target analytes. The implementation of PL-based sensing schemes combining multiple QDs of different nature, excited at the same wavelength and emitting at different ones, allowed to obtain a specific analyte-response profile. The first-order fluorescence data obtained from the whole emission spectra of the CdTe/AgInS2 combined nanoprobe upon interaction with folic acid and Fe(II) were processed by using chemometric tools, namely partial least-squares (PLS) and artificial neural network (ANN). This enabled to circumvent the selectivity issues commonly associated with the use of QDs prone to indiscriminate interaction with multiple species, which impair reliable and accurate quantification in complex matrices samples. ANN demonstrated to be the most efficient chemometric model for the simultaneous determination of both analytes in binary mixtures and pharmaceutical formulations due to the non-linear relationship between analyte concentration and fluorescence data that it could handle. The R2P and SEP% obtained for both analytes quantification in pharmaceutical formulations through ANN modelling ranged from 0.92 to 0.99 and 5.7e9.1%, respectively. The obtained results revealed that the developed approach is able to quantify, with high reliability and accuracy, more than one analyte in complex mixtures and real samples with pharmaceutical interest.

    关键词: CdTe/AgInS2 combined nanoprobe,Artificial neural network,Iron,Partial least-squares,Folic acid

    更新于2025-09-23 15:19:57

  • A novel electrochemiluminescence sensor based on resonance energy transfer system between nitrogen doped graphene quantum dots and boron nitride quantum dots for sensitive detection of folic acid

    摘要: Electrochemiluminescence resonance energy transfer (ECL-RET) between quantum dots (QDs) was firstly proposed. In this work, boron nitride quantum dots (BNQDs) as the donor and nitrogen doped graphene quantum dots (NGQDs) as the acceptor were confirmed by the absorption spectrum, the emission spectrum and fluorescence spectrum. Based on the reaction between FA and the SO4?? in the ECL system of NGQDs/BNQDs/K2S2O8, the ECL sensing platform for FA was successfully constructed. Surprisingly, a stable and strong ECL signal was obtained based on the RET, which was used for signal-off detection of FA in the presence of coreactant K2S2O8. Notably, about 10-fold enhancement was observed compared with the absence of BNQDs. The proposed sensor showed wide linear ranges of 1.0 × 10?11 M to 1.0 × 10?4 M and a low detection limit of 5.13 × 10?12 M. Simultaneously, the sensor was successfully applied to detection of FA in human serum samples with excellent recoveries. Therefore, the NGQDs/BNQDs system provided a new perspective for development of novel ECL-RET sensors.

    关键词: Folic acid,Nitrogen doped graphene quantum dots,Resonance energy transfer,Boron nitride quantum dots,Electrochemiluminescence

    更新于2025-09-16 10:30:52

  • Gold Nanoparticle-Mediated Generation of Reactive Oxygen Species During Plasmonic Photothermal Therapy: A Comparative Study for Different Particles Size, Shape, and Surface Conjugation

    摘要: Gold nanoparticles (AuNPs)-mediated photothermal therapy represents an alternative to the effective ablation of cancer cells. However, the photothermal response of AuNPs must be tailored to improve the therapeutic efficacy of plasmonic photothermal therapy (PPT) and mitigate its side effects. This study presents an alternative to ease the tuning of photothermal efficiency and target selectivity. We use laser-treated spherical and anisotropic AuNPs with different sizes and biocompatible folic acid (FA)-conjugated AuNPs (FA-AuNPs) in the well-known human epithelial cervical cancer (HeLa) cell line. We show that large AuNPs produce a more significant photothermal heating effect than small ones. The thermal response of spherical AuNPs of 9 nm was found to reach a maximum increase of 3.0 ± 1 °C, whereas, with spherical AuNPs of 14 nm, the temperature increased by over 4.4 ± 1 °C. Anisotropic AuNPs of 15 nm reached a maximum of 4.0 ± 1 °C, whereas anisotropic AuNPs of 20 nm reached a significant increase of 5.3 ± 1 °C in the cell culture medium (MEM). Notably, anisotropic AuNPs of 20 nm successfully demonstrates the potential for use as a photothermal agent by showing reduced viability down to 60% at a concentration of 100 μM. Besides, we reveal that high concentrations of reactive oxygen species (ROS) are formed within the irradiated cells. It is likely to give rise in combination with stress by photothermal heating, resulting in significant cell death through acute necrosis by compromising the plasma membrane integrity. Cell death and ROS overproduction during PPT were characterized and quantified using transmission electron microscopy (TEM) and confocal fluorescence microscopy with different fluorescent markers. In addition, we show that FA-AuNPs induce cell death through apoptosis by internal damage, whereas diminishing ROS formation during PPT treatment. Our findings suggest the ability of plasmon-mediated ROS to sensitize cancer cells and make them vulnerable to photothermal damage, as well as the protective role of FA-AuNPs from excessive ROS formation, whereas reducing the risk of undesired side effects due to necrotic death pathway. It allows an improvement in the efficacy of AuNP-based photothermal therapy and a reduction in the number of exposures to high temperatures required to induce thermal stress.

    关键词: Reactive oxygen species,Laser irradiation,Gold nanoparticles,Folic acid,Photothermal effect

    更新于2025-09-16 10:30:52

  • Folic Acid-conjugated nitrogen-doped graphene quantum dots as fluorescent diagnostic material for MCF-7 cells

    摘要: This paper reports the preparation and application of folic acid-conjugated nitrogen-doped graphene quantum dot as a fluorescent diagnostic material for MCF-7 cells of breast cancer. Nitrogen-doped graphene quantum dots (N-GQD) were prepared by hydrothermal method using citric acid as carbon source and diethylamine as nitrogen source. The doping of different nitrogen contents was effectively controlled by diethylamine. As the amount of nitrogen increased, more binding sites on the nitrogen-doped graphene quantum dots were supplied to the folic acid. Laser confocal scanning microscopy showed that the more folic acid binding facilitated the recognition and swallowing by cancer cells, which made the labeled cells emit stronger fluorescence and thus cancer cells could be better detected. Cytotoxicity tests showed that the material was low cytotoxic, making it a promising prospect for fluorescent probes.

    关键词: fluorescent diagnostic material,nitrogen-doped graphene quantum dots,folic acid

    更新于2025-09-12 10:27:22

  • Selective detection of folic acid in the midst of other biomolecules using water-soluble AgInS2 quantum dots

    摘要: We herein report the detection of folic acid (FA) via the fluorometric method using water-soluble AgInS2 quantum dots (QDs). The optical analysis showed that the addition of FA to AgInS2 QDs results in significant, blue-shifted photoluminescence emission. A linear plot of the blueshift in the photoluminescence wavelength position against FA concentration was obtained in the range of 0.03–33 μM with the detection limit of 52 nM. Interference study showed the selective detection of FA in the presence of other biomolecules. The as-synthesized AgInS2 QDs can be employed as an optical sensor for the rapid detection of FA in aqueous solutions.

    关键词: photoluminescence,fluorometric method,optical sensor,AgInS2 quantum dots,folic acid

    更新于2025-09-12 10:27:22

  • CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid

    摘要: In this paper, we report the synthesis, characterization, and application of a new fluorescent nanosensor based on water-soluble CdTe quantum dots (QDs) coated with cysteamine (CA) for the determination of folic acid (FA). CdTe/CA QDs were characterized by high-resolution transmission electron microscopy, the zeta potential, and Fourier-transform infrared (FT-IR), UV-visible, and fluorescence spectroscopy. CdTe QDs coated with mercaptopropionic acid (MPA) and glutathione (GSH) were prepared for comparison purposes. The effect of FA on the photoluminescence intensity of the three thiol-capped QDs at pH 8 was studied. Only CdTe/CA QDs showed a notable fluorescence quenching in the presence of FA. Then, a nanosensor based on the fluorescence quenching of the CdTe QDs at pH 8 was explored. Under optimum conditions, the calibration curve showed a linear fluorescence quenching response in a concentration range of FA from 0.16 to 16.4 μM (R2 = 0.9944), with a detection limit of 0.048 μM. A probable mechanism of fluorescence quenching was proposed. The nanosensor showed good selectivity over other possible interferences. This method has been applied for FA quantification in orange beverage samples with excellent results (recoveries from 98.3 to 103.9%). The good selectivity, sensitivity, low cost, and rapidity make CdTe /CA QDs a suitable nanosensor for FA determination.

    关键词: electron transfer,folic acid nanosensor,positive quantum dots,fluorescence quenching

    更新于2025-09-12 10:27:22

  • New 55Co-labeled Albumin-Binding Folate Derivatives as Potential PET Agents for Folate Receptor Imaging

    摘要: Overexpression of folate receptors (FRs) on di?erent tumor types (e.g., ovarian, lung) make FRs attractive in vivo targets for directed diagnostic/therapeutic agents. Currently, no diagnostic agent suitable for positron emission tomography (PET) has been adopted for clinical FR imaging. In this work, two 55Co-labeled albumin-binding folate derivatives-[55Co]Co-cm10 and [55Co]Co-rf42-with characteristics suitable for PET imaging have been developed and evaluated. High radiochemical yields (≥95%) and in vitro stabilities (≥93%) were achieved for both compounds, and cell assays demonstrated FR-mediated uptake. Both 55Co-labeled folate conjugates demonstrated high tumor uptake of 17% injected activity per gram of tissue (IA/g) at 4 h in biodistribution studies performed in KB tumor-bearing mice. Renal uptake was similar to other albumin-binding folate derivatives, and liver uptake was lower than that of previously reported [64Cu]Cu-rf42. Small animal PET/CT images con?rmed the biodistribution results and showed the clear delineation of FR-expressing tumors.

    关键词: folate receptors,cobalt-55,PET imaging,albumin binder,ovarian cancer,folic acid

    更新于2025-09-12 10:27:22