- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
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
-
Bi <sub/>2</sub> SiO <sub/>5</sub> @g-SiO <sub/>2</sub> upconverting nanoparticles: a bismuth-driven core–shell self-assembly mechanism
摘要： Core–shell systems have attracted increasing interest among the research community in recent years due to their unique properties and structural features, and the development of new synthetic strategies is still a challenge. In this work, we have investigated lanthanide-doped Bi2SiO5 nanocrystal formation inside mesoporous silica nanoparticles (MSNs). The role of both synthesis temperature and concentration of the bismuth precursor impregnated into the MSNs is discussed, showing an unprecedented strategy for the simultaneous stabilization of a crystalline core and a glassy shell. Temperature dependent synchrotron radiation X-ray powder diffraction (SR-XRPD) and high resolution transmission electron microscopy (HR-TEM) analyses allow one to follow the crystalline core growth. A mechanism for the formation of a Bi2SiO5@g-SiO2 core–shell nanosystem is proposed. In addition, the easy tunability of the color output of the upconverting system is demonstrated by means of suitable doping lanthanide ions with potential applications in several fields.
关键词： upconversion luminescence,mesoporous silica,core–shell nanoparticles,bismuth silicate,Bi2SiO5
更新于2025-09-19 17:15:36
-
The use of surfactant-filled mesoporous silica as an immobilising medium for a fluorescence lifetime pH indicator, providing long-term calibration stability
摘要： Surfactant filled mesoporous silica is applied as a matrix for immobilizing the fluorescence lifetime pH-indicator acridine. We demonstrate that this type of encapsulation provides a stable and uniform chemical environment for the indicator and has good proton transport properties leading to rapid pH response times. Furthermore, the immobilising medium effectively prevents leaching of the indicator, facilitates high long-term stability and does not influence the pH sensing-range of the indicator.
关键词： acridine,surfactant-filled mesoporous silica,fluorescence lifetime pH indicator,proton transport properties,long-term calibration stability
更新于2025-09-16 10:30:52
-
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
-
Bright emission and high photoluminescence CsPb <sub/>2</sub> Br <sub/>5</sub> NCs encapsulated in mesoporous silica with ultrahigh stability and excellent optical properties for white light-emitting diodes
摘要： All-inorganic cesium lead halide perovskite CsPb2Br5 nanocrystals (NCs) have attracted tremendous attention owing to their unique optoelectronic properties. However, their tolerance to atmospheric moisture is limited by their corresponding poor stability, which has drastically prevented the broad application of the materials in lasers, light-emitting diodes (LED) and, most recently, photocatalysis. To address this issue, we have successfully demonstrated the design and synthesis of a nanocomposite material, CsPb2Br5 NCs coated in mesoporous silica (NCs-MS), with high photoluminescence (PL) intensity, bright emission and enhanced water stability, thermal stability and photostability versus naked CsPb2Br5 NCs. The components and structure of the prepared CsPb2Br5 NCs-MS nanocomposite were investigated in detail by PL, XRD, TEM and HAADF-STEM studies. Furthermore, the mechanism behind the outstanding stability and optical properties of the prepared NCs-MS nanocomposite is discussed. Owing to the ultrahigh stability of the NCs-MS nanocomposite, the white LED (WLED) assembled by coating the CsPb2Br5 NCs-MS nanocomposite and commercial red CaAlSiN3:Eu2+ phosphor powder on an InGaN blue chip showed CIE chromaticity coordinates of (0.3377, 0.3309) and presented excellent optical parameters with a CRI of 82.9, a CCT of 5035 K and an LE of 64.9 lm W?1. This work provides a new pathway for the synthesis and application of all-inorganic cesium lead halide perovskite materials in WLEDs and display devices.
关键词： stability,white light-emitting diodes,mesoporous silica,photoluminescence,CsPb2Br5 NCs
更新于2025-09-16 10:30:52
-
Photo-induced generation of size controlled Au nanoparticles on pure siliceous ordered mesoporous silica for catalytic applications
摘要： A versatile in situ photochemical reduction approach was used to generate a composite of gold nanoparticles and pure siliceous SBA-15 silica support with regular mesopores. The mesoporous silica support was first synthesized and, after calcination, was suspended in a solution of gold bromide (EtOH or H2O) containing a free radical generator activated by UV irradiation and used for the photochemical reduction of gold precursor. The influence of gold precursor concentration, light intensity and nature of the solvents on the formation and properties of gold nanoparticles (size, dispersion, stability) on the mesoporous SBA-15 support have been studied with the aim of optimizing the dispersion of the gold nanoparticles in the mesoporous network and their chemical stability. The catalytic activity of the resulting AuNPs@SBA-15 nanocomposite was successfully evaluated for the oxidation of benzyl alcohol reaction in liquid-phase.
关键词： Benzyl alcohol,Photoreduction,Gold nanoparticles,Mesoporous silica,SBA-15,Oxidation
更新于2025-09-12 10:27:22
-
Reaction-probe infrared investigation on drastic change in reactivity of mesoporous silica for acetalization of cyclohexanone with methanol; pore-size dependence
摘要： Small-pored (< 2.5 nm) mesoporous silica showed remarkably higher catalytic activity for cyclohexanone acetalization with methanol than large-pored ones (≥2.5 nm). For the clari?cation of the pore-size e?ect of mesoporous silicas (MCM-41 and SBA-15) on the reactivity, the reaction probe infrared (IR) method was applied. No evident di?erences were observed by conventional IR characterization methods using CO, pyridine and acetonitrile adsorption. IR spectra of methanol, one of the reactants, on small-pored (MCM-41) and large-pored (SBA-15) samples appeared the same. On the other hand, adsorption of cyclohexanone resulted in di?erent IR spectra: a C]O stretching band appeared at lower frequency side on MCM-41 at a small amount of adsorption in addition to that observed on SBA-15. This result indicates the presence of the stronger interaction of cyclohexanone with MCM-41 than that with SBA-15. When the time course of the reaction was observed by in-situ IR observation, the consumption of activated carbonyl groups and the generation of 1,1-dimethoxycyclohexane, the reaction product, were con?rmed. The presence of the activated cyclohexanone was most probably due to the adsorption on two (or more) OH groups in vicinity, while a non-activated species occupied a single OH group. The reaction probe IR method is thus, a direct and e?ective approach to extract the small di?erences in catalysis.
关键词： Pore-size dependence,Acetalization,Infrared spectroscopy,Reaction-probe,Mesoporous silica
更新于2025-09-10 09:29:36
-
Hydrophilic Internal Pore and Hydrophobic Particle Surface of Organically Modified Mesoporous Silica Particle to Host Photochromic Molecules
摘要： The external surface of a mesoporous silica, MCM-41, was functionalized with phenyl group to obtain dual domain mesoporous silica particle (hydrophobic particle surface and hydrophilic mesopore) for photochrmoism of merocyanine/spiropyran. Merocyanine was adsorbed on MCM-41 and that functionalized with phenyl group by the photoinduced adsorption. The red hybrid of Ph-MCM-41 showed negative photochromism with a higher decolorization efficiency and a faster thermal colorization than the hybrid of MCM-41, suggesting the photogenerated spiropyran diffused into the hydrophobic surface.
关键词： Mesoporous silica,Surface modification,Negative photochromism
更新于2025-09-04 15:30:14
-
Photocatalytic activities using a nanocomposite of mesoporous SiO2 and CdInSe-graphene nanoparticles under visible light irradiation
摘要： The new novel ternary mesoporous SiO2/CdInSe-graphene composites with diameters of approximately 8.08 nm have been fabricated through a self-assembly method. All physical tests demonstrated that the CdInSe-graphene was successfully uniformly distributed onto the surface of the ordered mesoporous silica particles. The obtained mesoporous SiO2/CdInSe-graphene composites exhibited good photocatalytic activity for degradation of both cationic-anionic organic dye groups, as well as the decomposition of the representative phenol group of the compound under visible light irradiation. Moreover, the photocatalytic evolution of hydrogen was studied for establishing a wider application of the as-fabricated SiO2/CdInSe-graphene catalyst in the case of energy conversion. This work indicated that the combination of the mesoporous silica and CdInSe-graphene enables achievements such as an enhancement photocatalytic performance, which has potential in industrial waste management and energy conversion.
关键词： Dye decomposition,CdInSe nanoparticles,Graphene-based nanocomposite,Gallic acid degradation,Mesoporous silica,Hydrogen production
更新于2025-09-04 15:30:14
-
<i>In vivo</i> Imaging-Guided Nanoplatform for Tumor Targeting Delivery and Combined Chemo-, Gene- and Photothermal Therapy
摘要： Currently, a large number of anti-tumor drug delivery systems have been widely used in cancer therapy. However, due to the molecular complexity and multidrug resistance of tumors, monotherapies remain suboptimal. Thus, this study aimed to develop a multifunctional theranostic nanoplatform for effective cancer therapy. Methods: Folic acid-modified silver sulfide@mesoporous silica core-shell nanoparticle was first modified with desthiobiotin (db) on the surface, then doxorubicin (DOX) was loaded into pore. Avidin was employed as "gatekeeper" to prevent leakage of DOX via desthiobiotin-avidin interaction. Db-modified survivin antisense oligonucleotide (db-DNA) which could inhibit survivin expression was then grafted on avidin at the outer layer of nanoparticle. DOX release and db-DNA dissociation were simultaneously triggered by overexpressing biotin in cancer cells, then combining PTT from Ag2S QD to inhibit tumor growth. Results: This nanoprobe had satisfactory stability and photothermal conversion efficiency up to 33.86% which was suitable for PTT. Due to the good targeting ability and fluorescent anti-bleaching, its signal still existed at the tumor site after tail vein injection of probe into HeLa tumor-bearing nude mice for 48 h. In vitro and in vivo antitumor experiments both demonstrated that drug, gene and photothermal synergistic therapy significantly enhanced antitumor efficacy with minimal systemic toxicity. Conclusion: Our findings demonstrate that this novel nanoplatform for targeted image-guided treatment of tumor and tactfully integrated chemotherapy, photothermal therapy (PTT) and gene therapy might provide an insight for cancer theranostics.
关键词： mesoporous silica,photothermal therapy,fluorescence imaging,gene therapy,drug delivery system
更新于2025-09-04 15:30:14