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Glutathione- and light-controlled generation of singlet oxygen for triggering drug release in mesoporous silica nanoparticles
摘要： A combined stimuli-responsive photosensitiser and drug release system based on mesoporous silica nanoparticles was prepared. This nanoplatform encapsulated molecules of a zinc(II) phthalocyanine substituted with a glutathione-cleavable 2,4-dinitrobenzenesulfonate quencher and doxorubicin linked via a singlet-oxygen-cleavable 9,10-dialkoxyanthracene linker. In the presence of glutathione (in mM range) and upon irradiation (λ > 610 nm), the phthalocyanine units were activated by detaching from the quenching component to emit fluorescence and generate singlet oxygen. The latter subsequently cleaved the 9,10-dialkoxyanthracene linker to trigger the release of a doxorubicin derivative. The glutathione- and light-controlled activation and drug-release processes on this nanoplatform were demonstrated in phosphate buffered saline. The activation in fluorescence emission by intracellular thiols was also shown inside HepG2 human hepatocellular carcinoma cells. Upon irradiation, the nanosystem exhibited high cytotoxicity due to the photodynamic effect of the activated phthalocyanine units, but the cytotoxic effect of the released Dox moieties was not notable probably due to their reduced cytotoxicity as a result of the pendant substituent and the low drug loading in the nanoparticles.
关键词： mesoporous silica nanoparticles,photosensitiser,photodynamic therapy,doxorubicin,drug release,glutathione,singlet oxygen
更新于2025-09-23 15:19:57
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An improved class of fluorescent silica nanoparticles for indirect immunofluorescence detection of MCF-7?cells
摘要： In this work, we have developed an efficient method based on silica fluorescent dye-doped nanoparticles and second antibody for cancer cell labeling. The dye-doped silica nanoparticles were synthesized by the reverse microemulsion method with the conjugate of 3-aminopropyltriethoxysilane and rhodamine B isothiocynate. A PEG with flexible long chain as the bridge was introduced onto the surface of the nanoparticle via cyanogens bromide method. The second antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminal modified silica fluorescent nanoparticles by covalent binding to the PEG linkers via the EDC/sulfo-NHS method. The concentrations of goat anti-rabbit IgG covering the nanoparticles were quantified via the Bradford method. The silica fluorescent nanoparticles functionalized with rabbit anti-MUC1 antibody were employed as bioprobes for the recognition of MUC1 protein in human breast carcinoma molecules MCF-7 cells. Compared with fluorescent dye labeled IgG, the fluorescent nanoprobes display dramatically increased photostability.
关键词： MCF-7 cells,Dye-doped silica nanoparticles,Conjugation,Mucin,Bioprobe
更新于2025-09-23 15:19:57
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Fluorescein- and EGFR-Antibody Conjugated Silica Nanoparticles for Enhancement of Real-time Tumor Border Definition Using Confocal Laser Endomicroscopy in Squamous Cell Carcinoma of the Head and Neck
摘要： Intraoperative de?nition of tumor free resection margins in head and neck cancer is challenging. In the current proof-of-principle study we evaluated a novel silica nanoparticle-based agent for its potential use as contrast enhancer. We synthesized silica nanoparticles with an average size of 45 nm and modi?ed these particles with the ?uorescence stain ?uorescein isocyanate (FITC) for particle detection and with epidermal growth factor receptor (EGFR)-targeting antibodies for enhanced tumor speci?city. The nanoparticles exhibited good biocompatibility and could be detected in vitro and in vivo by confocal laser scanning microscopy. Additionally, we show in an ex vivo setting that these modi?ed nanoparticles speci?cally bind to tumor samples and could be detected using a handheld confocal ?uorescence endomicroscope. From a clinical point of view, we believe that this method could be used for tumor border contrast enhancement and for better intraoperative de?nition of R-0 tumor resection.
关键词： silica nanoparticles,EGFR,contrast agent
更新于2025-09-19 17:13:59
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AuNP and ssDNA capped mesoporous silica nanoparticles for laser controlled drug release
摘要： In order to improve drug e?cacy, and reduce drug toxicity and side e?ects, a novel drug controlled release system was developed based on mesoporous silica nanoparticles (MSNs) with gold nanoparticles (AuNPs) acting as pore caps and short single-stranded DNA (ssDNA) oligomers as the linker. The synthesised composites were characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray di?raction (XRD), thermogravimetric analysis (TGA), zeta potential measurement, transmission electron microscopy (TEM) and UV-vis spectroscopy. The anticancer drug doxorubicin (Dox) was applied as a model drug to investigate the 808 nm near infrared (NIR) laser-controlled drug release behavior at di?erent pH by ?uorescence measurements. The investigation results demonstrate that this nanocarrier could achieve drug controlled release by external near-infrared (NIR) laser stimulation, which is expected to be applied in cancer therapy.
关键词： doxorubicin,near-infrared laser,single-stranded DNA,mesoporous silica nanoparticles,drug controlled release,gold nanoparticles
更新于2025-09-16 10:30:52
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4-Mercaptobenzoic Acid Labeled Gold-Silver-Alloy-Embedded Silica Nanoparticles as an Internal Standard Containing Nanostructures for Sensitive Quantitative Thiram Detection
摘要： In this study, (4-mercaptobenzoic acid labeled SiO2@Au@4-MBA@Ag gold-silver-alloy-embedded silica nanoparticles) nanomaterials were investigated for the detection of thiram, a pesticide. First, the presence of Au@4-MBA@Ag alloys on the surface of SiO2 was confirmed by the broad bands of ultraviolet-visible spectra in the range of 320–800 nm. The effect of the 4-MBA (4-mercaptobenzoic acid) concentration on the Ag shell deposition and its intrinsic SERS (surface-enhanced Raman scattering) signal was also studied. Ag shells were well coated on SiO2@Au@4-MBA in the range of 1–1000 μM. The SERS intensity of thiram-incubated SiO2@Au@4-MBA@Ag achieved the highest value by incubation with 500 μL thiram for 30 min, and SERS was measured at 200 μg/mL SiO2@Au@4-MBA@Ag. Finally, the SERS intensity of thiram at 560 cm?1 increased proportionally with the increase in thiram concentration in the range of 240–2400 ppb, with a limit of detection (LOD) of 72 ppb.
关键词： gold–silver-alloy-embedded silica nanoparticles,internal standard,thiram,ultrasensitive detection
更新于2025-09-16 10:30:52
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Controlling Surface Chemical Heterogeneities of Ultrasmall Fluorescent Core–Shell Silica Nanoparticles as Revealed by High-Performance Liquid Chromatography
摘要： Ultrasmall (diameter below 10 nm) fluorescent core?shell silica nanoparticles have garnered increasing attention in recent years as a result of their high brightness and favorable biodistribution properties important for applications including bioimaging and nanomedicine. Here, we present an in-depth study that provides new insights into the physical parameters that govern full covalent fluorescent dye encapsulation within the silica core of poly(ethylene glycol)-coated core?shell silica nanoparticles referred to as Cornell prime dots (C′ dots). We use a combination of high-performance liquid chromatography (HPLC), gel-permeation chromatography, and fluorescence correlation spectroscopy to monitor the result of ammonia concentration in the synthesis of C′ dots from negatively and positively charged versions of near-infrared dyes Cy5 and Cy5.5. HPLC, in particular, allows the distinction between cases of full versus partial dye encapsulation in the silica particle core leading to surface chemical heterogeneities in the form of hydrophobic surface patches, which, in turn, modulate biological response in ferroptotic cell death experiments. Our results demonstrate that there is a complex interplay between dye?dye and dye?silica cluster interactions originally formed in the sol?gel synthesis governing optimal dye encapsulation. We expect that the reduced surface chemical heterogeneities will make the resulting nanoparticles attractive for a number of applications in biology and medicine.
关键词： gel-permeation chromatography,ferroptotic cell death,high-performance liquid chromatography,fluorescent core?shell silica nanoparticles,fluorescence correlation spectroscopy
更新于2025-09-11 14:15:04
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Interfacial uploading of luminescent hexamolybdenum cluster units onto amino-decorated silica nanoparticles as new design of nanomaterial for cellular imaging and photodynamic therapy
摘要： The present work introduces a facile synthetic route to embed phosphorescent K2[{Mo6I8}I6] and (nBu4N)2[{Mo6I8}(CH3COO)6] clusters (C) onto silica-water interface of amino-decorated silica nanoparticles (SNs, 60±6 nm). The assembled C-SNs gain in the luminescence intensity, which remains stable within three months after their assembly. High uptake capacity of the clusters (8700 of K2[{Mo6I8}I6] and 6500 of (nBu4N)2[{Mo6I8}(CH3COO)6] per the each nanoparticle) derives from ionic self-assembly and coordination bonds between the cluster complexes and ionic (amino- and siloxy-) groups at the silica surface. The coordination via amino- or siloxy-groups restricts aquation and hydrolysis of the embedded clusters, in comparison with the parent K2[{Mo6I8}I6] and (nBu4N)2[{Mo6I8}(CH3COO)6. High potential of the assembled nanoparticles in the ROS generation was revealed by EPR measurements facilitated by spin trapping. The high positive charge and convenient colloid stability of the assembled C-SNs hybrids are the prerequisite for their efficient cellular uptake, which is exemplified in the work by MCF-7 cell line. The measured dark and photoinduced cytotoxicity of the C-SNs hybrids reveals significant photodynamic therapy effect on the MCF-7 cancer cell line versus the normal cells. This effect is entirely due to the embedded clusters and is dependent on the chemical composition of the cluster.
关键词： hexamolybdenum cluster,adsorption,silica nanoparticles,cell internalization,photodynamic therapy,luminescence
更新于2025-09-10 09:29:36
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Silica Nanoparticles with Up-conversion Fluorescence Based on Triplet-Triplet Annihilation Mechanism for Specific Recognition of Apoptosis Cells
摘要： Discriminating of live and apoptotic cells is a crucial task in the research of pharmacology, biology, pathology, and medicine science. Recently, up conversion (UC) luminescent materials have appealed much attention due to their unique ability to convert low energy excitation photons to high energy ones. However, UC fluorescence has not been employed in the field of discriminating of live and apoptotic cells. We presented a facile, and cost-less St?ber method to fabricate robust silica nanoparticles (SiO2 UCNPs) exhibiting several merits, such as narrow size distribution, and UC luminescence. SiO2 UCNPs could discriminate live and apoptosis cells by taking advantage of the unique surface property of SiO2 UCNPs for the first time. This work is also the first demonstration of the use of single photon excited UC fluorescence derived from nanoparticles for biological recognition of a specific type of cells.
关键词： Apoptosis Cells,Triplet-Triplet Annihilation Mechanism,Silica Nanoparticles,Up-conversion Fluorescence
更新于2025-09-09 09:28:46
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Amorphous Quantum Nanomaterials
摘要： In quantum materials, macroscopic behavior is governed in nontrivial ways by quantum phenomena. This is usually achieved by exquisite control over atomic positions in crystalline solids. Here, it is demonstrated that the use of disordered glassy materials provides unique opportunities to tailor quantum material properties. By borrowing ideas from single-molecule spectroscopy, single delocalized π-electron dye systems are isolated in relatively rigid ultra-small (<10 nm diameter) amorphous silica nanoparticles. It is demonstrated that chemically tuning the local amorphous silica environment around the dye over a range of compositions enables exquisite control over dye quantum behavior, leading to efficient probes for photodynamic therapy (PDT) and stochastic optical reconstruction microscopy (STORM). The results suggest that efficient fine-tuning of light-induced quantum behavior mediated via effects like spin-orbit coupling can be effectively achieved by systematically varying averaged local environments in glassy amorphous materials as opposed to tailoring well-defined neighboring atomic lattice positions in crystalline solids. The resulting nanoprobes exhibit features proven to enable clinical translation.
关键词： photodynamic therapy (PDT),optical super-resolution microscopy,organic dyes,amorphous silica nanoparticles
更新于2025-09-04 15:30:14
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Confinement of Singlet Oxygen Generated from Ruthenium Complex-Based Oxygen Sensor in the Pores of Mesoporous Silica Nanoparticles
摘要： We synthesized mesoporous silica nanoparticles bearing ruthenium complexes in their pores (MSN-Ru) and characterized their photochemical properties. The ruthenium complexes that were immobilized in the pores showed oxygen-dependent phosphorescence, similar to the complexes that were not tethered to nanoparticles. Cellular imaging and in vivo experiments revealed that hypoxic cells and tissues could be visualized by monitoring the phosphorescence of MSN-Ru. Our most important finding was that the toxic effect of singlet oxygen (1O2), which was generated by excitation of the complexes, was effectively suppressed by the deactivation before leaking out from the pores. In addition, we observed a negligible toxic effect of the ruthenium complexes themselves due to the blockage of their direct interaction with intracellular biomolecules. Thus, MSN-Ru is a promising molecular probe of oxygen levels in living cells and tissues.
关键词： ruthenium complexes,singlet oxygen,in vivo experiments,cellular imaging,oxygen sensor,mesoporous silica nanoparticles
更新于2025-09-04 15:30:14