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Multifunctional luminescent immuno-magnetic nanoparticles: toward fast, efficient, cell-friendly capture and recovery of circulating tumor cells
摘要： Highly efficient isolation and recovery of viable circulating tumor cells (CTCs) from the blood of patients is an important precondition to address the current dilemma of insufficient CTC studies, and can promote the development of individualized antitumor therapies. Herein, a cell-friendly CTC isolation and recovery nanoplatform with luminescent labelling was established using a layer-by-layer (LbL) assembly technique and a stimulated cellular-release strategy. In particular, the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody was introduced with a disulfide bond-containing linker for further bio-friendly recovery of the CTCs. Quantum dots (QDs) were deposited onto fast magnet-responsive Fe3O4 nanoparticles through a facile LbL assembly method to monitor the capture and recovery process in real time. The obtained PEGylated immuno-magnetic nanospheres (PIMNs) can all be magnetically collected within 2 min. Capture efficiencies above 90% can be achieved from blood samples with 5–200 CTCs per mL after only 1–2 min incubation. Nearly all PIMNs on the surface of the CTCs were detached after 15 min of glutathione (GSH) treatment with the disappearance of QD signals. Recovered CTCs could be directly used for culture (cell viability, 98%), and their invasiveness and migration characteristics remained unchanged. Furthermore, the PIMNs were successfully applied to isolate CTCs in cancer patients’ peripheral blood samples, and an average of 8.6 ± 5.8 CTCs per mL was detected. The results above suggested that PIMNs may serve as a powerful nanoplatform for CTC screening, isolation and recovery.
关键词： layer-by-layer assembly,circulating tumor cells,capture and recovery,Multifunctional luminescent immuno-magnetic nanoparticles,quantum dots,glutathione treatment
更新于2025-09-19 17:15:36
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Cu2+-mediated Fluorescence Switching of Graphene Quantum Dots for Highly Selective Detection of Glutathione
摘要： As a short peptide containing active thiol group, glutathione (GSH) participates in many cellular reactions, so it is of great significance to detect cellular GSH. In this work, amino-rich graphene quantum dots (GQDs) were synthesized, which could coordinate with copper ions (Cu2+) and yield aggregation-induced fluorescence quenching. However, GSH owns stronger coordination ability with Cu2+, so that GSH could promote the dissociation of Cu2+ from the surface of GQDs, and then led to the fluorescence recovery of GQDs. In BR buffer medium at pH 6.8, GSH was able to gradually recover the fluorescence of GQDs (1 μg/mL) that was quenched by Cu2+ (250 μmol/L), which could be finished within 20 min. Additionally, the recovery degree of fluorescence was linear to the concentration of GSH in the range of 20─500 μmol/L with a detection limit of 3.4 μmol/L. This method was applicable to the detection of GSH in cell lysate by the switchable function of Cu2+ to improve the selectivity.
关键词： Graphene quantum dots,Fluorescence switching,Copper ions,Glutathione
更新于2025-09-19 17:13:59
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Synthesis of Glutathione Modified CdSe Quantum Dots and Its Application in Determination of Trace Hg2+ Ions
摘要： The water-soluble glutathione (GSH) modified CdSe quantum dots (QDs) were prepared. Results show that the optimum NaBH4:Se:(Cd2+): glutathione molar ratio is obtained to be 3:1:3:9. Meanwhile, the glutathione modified CdSe quantum dots synthesized by the optimum process have a single face centered cubic phase. It is found that the fluorescence quenching occurred as Hg2+ ions interact with glutathione modified CdSe quantum dots. Hg2+ ions can be determined in the concentration range of 0.3-15 μg/L, which is proposed to determine the trace quantities of Hg2+ ions as fluorescence probe.
关键词： Glutathione,Quantum dots,Fluorescence probe,CdSe
更新于2025-09-16 10:30:52
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AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Solid lipid nanoparticles made of self-emulsifying lipids for efficient encapsulation of hydrophilic substances
摘要： In the last decades, most attention has been paid to solid lipid nanoparticles (SLN) as nanocarriers for pharmaceutical purposes due to their low toxicity, possible production on large scale and delivery of active principles by several administration routes. For example, lung delivery will necessitate direct administration, e.g. by aerosolisation, to maximize deposition into the airways and minimize systemic side effects. However, SLN based on common solid lipids preferentially incorporate lipophilic drugs, while the hydrophilic ones are loaded in low amount. To overcome this drawback, it seemed interesting to evaluate SLN based on self-emulsifying (SE) lipids, which are mixtures of lipids, surfactant and cosurfactants able to form emulsions in contact with aqueous media. Thus, we evaluated the preparation of SLN based on Gelucire? 50/13, selected as a SE lipid model, encapsulating glutathione (GSH) or proanthocyanidins occurring in grape seed extract (GSE), as hydrophilic model substances according to the melt-emulsification method. The encapsulation efficiency of such GSH- or GSE-SLN resulted satisfactory for both the hydrophilic compounds examined. However, to draw definitive conclusions on the scope and limitations of this approach based on SE lipids, further studies are necessary. Moreover, GSH-SLN were investigated for their performance in delivering the antioxidant peptide to immunocompetent fish cells, while GSE-SLN were evaluated for their possible application in the treatment of pulmonary diseases. It was found that GSH-SLN were not internalized by fish cells, while GSE-SLN showed favorable properties for lung delivery.
关键词： lung delivery,proanthocyanidins,solid lipid nanoparticles,self-emulsifying lipids,hydrophilic substances,encapsulation,glutathione
更新于2025-09-11 14:15:04
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Fluorescent Nanosensors Based on Colloidal Quantum Dots for the Determination of Reduced Glutathione
摘要： A ? uorescent nanosensor based on colloidal quantum dots CdSe/ZnS modi? ed with mercaptoacetic acid to determine reduced glutathione, a non-protein compound that plays an important role in protection against oxidative stress, is developed. Sample preparation protocols that allow determination of reduced glutathione in a wide range of concentrations are presented. Dependence of the ? uorescence intensity of the system on the incubation time for a number of concentrations of reduced glutathione was measured. The possibility of using the proposed nanosensor for reliable and sensitive determination of reduced glutathione in the concentration range from 10 to 1000 μM is con? rmed. The results can be used for quantitative determination of reduced glutathione in physiological media, which is of considerable interest for medical diagnostics.
关键词： quantum dots,nanoparticles,optical nanosensors,? uorescence,reduced glutathione,disease markers,medical diagnostics
更新于2025-09-11 14:15:04
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Locked Nucleic Acid Nanomicelle with Cell-Penetrating Peptides for Glutathione-Triggered Drug Release and Cell Fluorescence Imaging
摘要： Herein, we constructed a multi-functional spherical nanomicelle drug delivery system to improve the efficiency of cell uptake. The paclitaxel (PTX)-locked nucleic acid (LNA) monomer and the carboxyfluorescein (FAM)-labeled DNA was mixed together to assemble and form a spherical nanomicelle which was functionalized with transactivator of transcription (TAT), a cell-penetrating peptides (CPPs). A bioreductively activated disulfide was used to link the hydrophobic PTX to the LNA, allowing the PTX to be released freely in the presence of glutathione (GSH) upon cell uptake. Based on magnetic separation, synthetic process of PTX-LNA monomers avoid time-consuming and labor-intensive shortcoming. Cellular uptake of PTX-LNA-TAT nanomicelle and the drug release occur rapidly as proved by fluorescence microscopy and flow cytometry. The resulting nanomicelle was greater stability, monodisperse size, and the high therapeutic potential. Furthermore, the system can readily achieve detection of GSH in the cancer cells. The detection limit for commercial GSH determined was 1.0×10-9 M by using PTX/Fluorescein isothiocyanate (FITC)-LNA/ black hole quencher 1 (BHQ-1) as a probe.
关键词： glutathione,delivery system,locked nucleic acid,magnetic separation,transactivator of transcription peptide
更新于2025-09-09 09:28:46
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Media Dependent Switching of Selectivity and Continuous Near Infrared Turn-on Fluorescence Response through Cascade Interactions from Noncovalent to Covalent Binding for Detection of Serum Albumin in Living Cells
摘要： Abnormal level of proteins is proved to be associated with diseases. Thus, protein sensing is helpful for clinical diagnosis and therapy. However, there is a great variety of protein species and relatively low concentration of each protein in complicated biological systems including other non-protein biomolecules. Therefore, it remains challenging to develop an effective method for detecting protein with high selectivity and sensitivity. Herein, a new self-assembly method based on a robust dye SQSS of which two squaraine molecules were conjugated through disulfide bond was developed for highly selective and sensitive detection of serum albumin (SA) in aqueous solution and live cells. SQSS can self-assemble into “compact” aggregates, offering “inert” disulfide group and very low background fluorescence through the combination of aggregation quenching and homogeneous fluorescence resonance energy transfer (homoFRET) quenching. The response of SQSS to SA undergoes two cascade stages. At the first stage, SA drives the compact assemblies of SQSS to form loose ones with fast speed (30 s) through noncovalent interaction, resulting in the enhancement of fluorescence to some extent. In this loose assembly state, the disulfide bond in SQSS is reactive. At the second stage, the Cys34 in SA slowly induced further disassembly through covalent binding with reactive disulfide bond, resulting in fluorescence further increasing and SQSS labeling to SA that cannot be displaced by site binding ligands of SA. The self-assemblies of SQSS can selectively detect SA with continuous near infrared (NIR) turn-on fluorescence response in 100% aqueous buffer solution. In addition, SQSS showed the potential application of imaging SA in living cells. On the other hand, the loose assembly state of SQSS was also achieved in aqueous solution with 20% CH3CN. In this media, thiol-containing glutathione (GSH) caused the disassembly of SQSS with turn-on fluorescence response through interaction with disulfide bond. SQSS can selectively recognize GSH over other amino acids even in the presence of other sulfhydryl amino acids. As a proof-of-concept method, the molecular self-assembly through multi-steps interactions would provide an ideal strategy for detection and live-cell imaging of bio-related molecules with high selectivity and signal-to-noise ratio.
关键词： squaraine dyes,disulfide linkage,glutathione,live-cell imaging,serum albumin,self-assemblies,noncovalent and covalent interactions
更新于2025-09-09 09:28:46
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<i>In My Element</i> : Selenium
摘要： Selenium-rich foods are very popular in southern China, such as Se-rich oranges, tea, rice and mushrooms. As southern China has Se-rich soils, Se can be bioconcentrated by orange and tea trees or by rice and mushrooms growing in these soils. It holds true with many other plants grown in these Se-rich soils, and their fruits are believed to be Se-rich too. Eating Se-rich food every day is considered beneficial to our health because of its antioxidant effect.
关键词： redox-responsive,diselenide,dynamic covalent bonds,drug delivery,micronutrient,Selenium,Keshan disease,dendrimer,antioxidant,glutathione peroxidase
更新于2025-09-04 15:30:14