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1.
Although number of stimuli-responsive drug delivery systems based on mesoporous silica nanoparticles (MSNs) have been developed, the simultaneous real-time monitoring of carrier in order to guarantee proper drug targeting still remains as a challenge. GQDs-MSNs nanocomposite nanoparticles composed of graphene quantum dots (GQDs) and MSNs are proposed as efficient doxorubicin delivery and fluorescent imaging agent, allowing to monitor intracellular localization of a carrier and drug diffusion route from the carrier.Graphene quantum dots (average diameter 3.65?±?0.81 nm) as a fluorescent agent were chemically immobilized onto mesoporous silica nanoparticles (average diameter 44.08?±?7.18 nm) and loaded with doxorubicin. The structure, morphology, chemical composition, and optical properties as well as drug release behavior of doxorubicin (DOX)-loaded GQDs-MSNs were investigated. Then, the in vitro cytotoxicity, cellular uptake, and intracellular localization studies were carried out. Prepared GQDs-MSNs form stable suspensions exhibiting excitation-dependent photoluminescence (PL) behavior. These nanocomposite nanoparticles can be easily DOX-loaded and show pH- and temperature-dependent release behavior. Cytotoxicity studies proved that GQDs-MSNs nanocomposite nanoparticles are nontoxic; however, when loaded with drug, they enable the therapeutic activity of DOX via its active delivery and release. GQDs-MSNs owing to their fluorescent properties and efficient in vitro cellular internalization via caveolae/lipid raft-dependent endocytosis show a high potential for the optical imaging, including the simultaneous real-time optical tracking of the loaded drug during its delivery and release.
Graphical abstract ?
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2.
In this paper, the monodisperse silica nanoparticles were prepared by ultrasonic-assisted Stober method, and it explained that the ultrasonic cavitation effect shortened the reaction time from the original hours to f5 min. The effects of ultrasonic time, ultrasonic power, and stirring speed on the morphology, composition, and specific surface area of silica nanoparticles were investigated by field emission electron microscopy (FE-SEM). The results showed that nanoparticles with the best dispersity and the most uniform morphology were obtained under the optimized conditions (ultrasonic time is 5 min, ultrasonic power is 160 W, and the magnetic stirring speed is 999 rpm). The phase composition of SiO2 was characterized by high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), nano-size/zeta potential analyzer, and Fourier transform infrared spectroscopy (FT-IR). It showed that all typical peaks of samples are in line with the SiO2 spectrum, the particle size distribution and zeta potential value of the silica is 615?±?35.6 nm and 59.87?±?0.91 mv, respectively, which further verified that the spherical silica nanoparticles with good dispersity can be synthesized in a very short time. Hemolysis test showed that nano-SiO2 had high blood compatibility and biocompatibility when its concentration was less than 1 mg/mL. Doxorubicin (DOX·HCl) was regarded as a drug model to investigate the drug loading capacity of synthesized SiO2; the results showed that the drug loading capacity and encapsulation efficiency reached 42.6?±?1.2 and 85.2?±?2.5%, respectively. Furthermore, the drug release experiments fitted well with the Higuichi equation with correlation coefficient (R2) of 0.9984, which further confirmed that the SiO2/DOX drug delivery system has the controlled release property, and it also displayed pH-responsive behavior (at 96 h, the cumulative release of SiO2/DOX in PBS solution with pH 7.4, 6.5, and 5.0 was 48.33, 62.31, and 94.86%, respectively). Therefore, this paper provides the possibility for developing more effective, safer, and more targeted controlled drug carriers.  相似文献   

3.
A microcapillary reactor with 320 μm inner diameter was utilized for CdSe nanoparticle synthesis. The influence of the reaction temperature and flow rate of precursors on the size and size distribution of prepared CdSe nanoparticles was systematically studied. The as-prepared nanoparticles exhibit sharp excitonic absorption and photoluminescence peak (FWHM 30 nm) with a quantum-yield around 10–40%. The microcapillary reactor was also used for CdSe/ZnS core-shell nanoparticle synthesis in continuous-flow mode. The quantum yield of the core-shell nanoparticles was found to be considerably influenced by the reactor temperature and have a close correlation with the thickness of ZnS shell under growth. An optimized quantum yield up to 70% was obtained for the CdSe/ZnS core-shell nanoparticles.  相似文献   

4.
Luminescent core-shell europium(III)-silica nanoparticles were prepared using europium(III) chelate core structure and polyvinylpyrrolidone synthesis strategy for silica shell. Europium(III):naphtoyltrifluoroacetone:trioctylphosphineoxide complex was spontaneously agglomerated from organic solvent to water. Polyvinylpyrrolidone was adsorbed onto the core structure and stable silica shell was synthesized using tetraethylorthosilicate. Nanosized particles with a diameter of 71 ± 5 nm and 11 nm shell thickness were obtained with fluorescence decay rate of 517 μs and excitation and emission wavelengths of 334 and 614 nm, respectively.  相似文献   

5.
Hepatocellular carcinoma (HCC) is the most common form of liver cancer, occurring primarily in regions where viral hepatitis infections are common. Unfortunately, most HCC cases remain undiagnosed until late stages of the disease when patient outcome is poor, typically limiting survival from a few months to a year after initial diagnosis. In order to better care for HCC patients, new target-specific approaches are needed to improve early detection and therapeutic intervention. In this work, polymeric nanoparticles functionalized with a HCC-specific aptamer were examined as potential targeted drug delivery vehicles. Specifically, doxorubicin-loaded nanoparticles were prepared via nanoprecipitation of blends of poly(lactic-co-glycolic acid)-b-poly(ethylene glycol). These particles were further functionalized with the HCC-specific TLS11a aptamer. The in vitro interaction and therapeutic efficacy of the aptamer and aptamer-functionalized nanoparticles were characterized in a hepatoma cell line. Nanoparticles were found to be spherical in shape, roughly 100–125 nm in diameter, with a low polydispersity (≤0.2) and slightly negative surface potential. Doxorubicin was encapsulated within the particles at ~40 % efficiency. Drug release was found to occur through anomalous transport influenced by diffusion and polymer relaxation, releasing ~50 % doxorubicin in the first 10 h and full release occurring within 36 h. Confocal microscopy confirmed binding and attachment of aptamer-targeted nanoparticles to the cell surface of cultured HCC cells. Efficacy studies demonstrated a significant improvement in doxorubicin delivery and cell-killing capacity using the aptamer-functionalized, drug-loaded nanoparticles versus controls further supporting use of aptamer nanoparticles as a targeted drug delivery system for HCC tumors.
Graphical abstract In this work, polymeric nanoparticles functionalized with a liver cancer-specific aptamer were examined as potential targeted drug delivery vehicles. The aptamer-functionalized nanoparticles were found to significantly improve doxorubicin drug delivery and cell-killing capacity in vitro versus non-targeted controls, supporting their use as a targeted treatment toward liver cancer tumors.
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6.
Mesoporous silica nanoparticles (MSNs) have a network of pores that give rise to extremely high specific surface areas, making them attractive materials for applications such as adsorption and drug delivery. The pore topology can be readily tuned to achieve a variety of structures such as the hexagonally ordered Mobil Crystalline Material 41 (MCM-41) and the disordered “wormhole” (WO) mesoporous silica (MS) structure. In this work, the effects of pore topology and iron oxide core on doxorubicin loading and release were investigated using MSNs with pore diameters of approximately 3 nm and sub-100 nm particle diameters. The nanoparticles were loaded with doxorubicin, and the drug release into phosphate-buffered saline (PBS, 10 mM, pH 7.4) at 37 °C was monitored by fluorescence spectroscopy. The release profiles were fit using the Peppas model. The results indicated diffusion-controlled release for all samples. Statistically significant differences were observed in the kinetic host–guest parameters for each sample due to the different pore topologies and the inclusion of an iron oxide core. Applying a static magnetic field to the iron oxide core WO-MS shell materials did not have a significant impact on the doxorubicin release. This is the first time that the effects of pore topology and iron oxide core have been isolated from pore diameter and particle size for these materials.
Graphical abstract Comparison of the release of doxorubicin from WO and iron oxide@WO particles into PBS
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7.
Organic-inorganic composite microspheres with PS as a core and CeO2 nanoparticles as a shell were synthesized by in situ decomposition reaction of Ce(NO3)3 on the surfaces of PS microspheres prepared through soap-free emulsion polymerization. The shell thickness of the composite microspheres could be turned by varying the concentration of Ce(NO3)3 in the reaction solution. The whole process required neither surface treatment for PS microspheres nor additional surfactant or stabilizer. The as-synthesized PS/CeO2 composite microsphere samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Oxide chemical mechanical polishing (CMP) performance of the PS/CeO2 composite abrasives with different shell thickness was characterized by atomic force microscopy (AFM). The results indicated that the as-prepared core-shell structured composite microspheres (220-260 nm in diameter) possessed thin shell (10-30 nm) composed of CeO2 nanoparticles (particle diameter of 5-10 nm), and the final CeO2 contents of the composite microspheres ranged from 10 to 50 wt%. A possible mechanism for the formation of PS/CeO2 composite microspheres was discussed also. The CMP test results confirmed that the novel core-shell structured composite abrasives are useful to improve oxide CMP performance. In addition, there is an obvious effect of shell thickness of the composite abrasives on oxide CMP performance.  相似文献   

8.
Fe clusters have been synthesised in ultra-high-vacuum chamber using a gas-stabilized cluster aggregation method that ensures good control of the cluster size and naturally oxidized in order to obtain Fe/Fe oxide core-shell nanoparticles. The morphology of an individual nanoparticle, as revealed by transmission electron microscopy, consists of a Fe core of an average diameter of 4.4 nm surrounded by an oxide shell of uniform thickness of about 1.2 nm in average. The nanoparticles may be assimilated with a ferro-/antiferromagnetic (FM/AF) system. The morpho-structural features have been correlated with magnetic measurements on the core-shell nanoparticles. A significant exchange bias effect has been measured, when the sample was field-cooled under an applied field of 3 T. As the morphology of core-shell nanoclusters is much more complicated than in FM/AF bilayers of regular thickness due to the particular geometry of the coronal AF layer, the shape and surface anisotropy have to be taken into account for a correct interpretation of the magnetic data.  相似文献   

9.
《Physics letters. A》2019,383(21):2542-2550
Present research interest is to highlight on the manufacturing of core-shell nanoparticles because of core activity with unique properties and surface modification by a shell in the diverse fields (e.g. optoelectronic, catalysis and magneto-optics). In addition, the combined optical properties of magnetic-plasmonic core-shell NPs make them ideal candidates for many applications in biomedical fields. The influence of Fe-core and Au-shell for the formation of the core-shell viz. spherical and spheroidal nanostructures is studied using the discrete dipole approximation method. DDA is an approximation method and its accuracy is compared to Mie theory results for spherical core-shell NPs as Mie theory gives the exact solution to spherical targeted NPs. DDA calculations are further extended to spheroidal core-shell nanostructures. It is observed that the localized surface plasmon resonance (LSPR) peak position in considered core-shell nanostructures is enhanced by changing the cores and shell thickness in the core-shell spherical nanostructures and aspect ratio as well as shell thickness in spheroidal core-shell nanostructures. The absorption spectra are found between 363–788 nm wavelength ranges and can be tuned into UV-visible-near-infrared region of the electromagnetic (EM) spectrum in accordance with desired applications. It has been found that the Fe@hollow@Au and prolate core-shell nanostructures show enhancement to LSPR peaks, bandwidth and their corresponding intensities in comparison to other considered spherical and spheroidal core-shell nanostructures. Tunability in core size, shell thickness, aspect ratio, and configuration will open new potential uses of suitable magnetic-plasmonic core-shell nanostructures in cancer therapy, tissue engineering, drug delivery, and many more of biomedical fields.  相似文献   

10.
Multifunctional nanoparticles for selectively targeting tumor cells and effectively delivering multiple drugs are urgently needed in cancer therapy. Here, a dual‐drug delivery system is prepared, based on functionalized hollow mesoporous silica nanoparticles (HMSNs). Doxorubicin (DOX) hydrochloride is loaded into the hollow core, and dichloro(1,2‐diaminocyclohexane)platinum (II) (DACHPt) is stored in the pores of the shell by the coordination interaction with the carboxyl groups modified on the pore walls, which also serves as barriers to control the DOX release. Detailed studies in vitro indicate that the DACHPt release is triggered by Cl? through the cleavage of the coordination interaction, and the DOX release depends on the release rate of DACHPt and the environmental pH value. The surface of the mechanized nanoparticles is also modified by transferrin (Tf) to achieve the tumor specificity. Compared with individual drug delivery systems, the dual‐drug delivery system shows synergistic efficacy on the cell cytotoxicity (combination index = 0.30), resulting in improved tumor cell killing. The present dual‐drug delivery system provides a promising strategy to develop controlled and targeted combination therapies for efficient cancer treatment.  相似文献   

11.
A simple and highly efficient method is developed for the one-step in situ preparation of carbon-encapsulated MoO2 nanocrystals (MoO2@C) with core-shell structure for high-performance lithium-ion battery anode. The synthesis is depending on the solid-state reaction of cyclopentadienylmolybdenum tricarbonyl dimer with ammonium persulfate in an autoclave at 200 °C for 30 min. The large amount of heat generated during the explosive reaction cleaves the cyclopentadiene ligands into small carbon fragments, which form carbon shell after oxidative dehydrogenation coating on the MoO2 nanocrystals, resulting in the formation of core-shell structure. The MoO2 nanocrystals have an equiaxial morphology with an ultrafine diameter of 2–8 nm, and the median size is 4.9 nm. Hundreds of MoO2 nanocrystals are encapsulated together by the worm-like carbon shell, which is amorphous and about 3–5 nm in thickness. The content of MoO2 nanocrystals in the nanocomposite is about 69.3 wt.%. The MoO2@C anode shows stable cyclability and retains a high reversible capacity of 443 mAh g?1 after 50 cycles at a current density of 3 A g?1, owing to the effective protection of carbon shell.  相似文献   

12.
Irradiation effect of low-energy ion beam has been investigated on nanocoating developed with silica, titania and silica–titania core–shell nanoparticles embedded in an organic binder for nanopaint application. In this work, we have taken polyurethane as a model organic binder. Silica nanoparticles have been prepared through sol–gel synthesis with a particle size of 85?nm. Titania and core–shell nanoparticles have been prepared through both sol–gel and peptization process. Particle sizes obtained were 107?nm for titania and 240?nm for core–shell nanoparticles prepared through sol–gel process and 75?nm for TiO2 and 144?nm for core–shell nanoparticles prepared through peptization process. The coating formulations were developed with the above nanoparticles individually and nanoparticle concentration was varied from 1 to 6?wt% and the best performance in terms of hydrophobicity was obtained with 4?wt % of the nanoparticles in polyurethane coating formulation. All the coating formulations prepared were applied on a glass substrate and dried at 100°C. The dry film thickness obtained was around 100?µm in each case. These films dried on glass substrate were irradiated by nitrogen and argon ion beam with energy of 26?keV at fluences of 1014 to 1016?ions/cm2. The anti-algal property of the irradiated samples was improved and hydrophobicity was reduced.  相似文献   

13.
In this Rapid Communication, we present the development of monodisperse core-shell (silver core-silica shell) nanoparticles with various shell thicknesses featuring a fluorophore, subsequently named Metal-Enhanced Fluorescence (MEF) nanoballs. MEF nanoballs consist of a ≈130 nm silver nanoparticle core, a silica shell with up to 35 nm thickness and fluorophores doped within the silica shell. Fluorescent nanobubbles where the silver core is removed by chemical etching are used as control samples to show the benefits of using silver nanoparticles, i.e, Metal-Enhanced Fluorescence. Finally, we demonstrate the broad potential biological applications of MEF nanoballs by employing near-infra red emitting probes (Rhodamine 800) within the silica shell, for potential applications in cellular imaging and solution-based sensing. Kadir Aslan, Meng Wu, Contributed equally  相似文献   

14.
Obtaining small (<50 nm), monodispersed, well-separated, single iron oxide core–silica (SiO2) shell nanoparticles for biomedical applications is still a challenge. Preferably, they are synthesised by inverse microemulsion method. However, substantial amount of aggregated and multicore core–shell nanoparticles is the undesired outcome of the method. In this study, we report on the production of less than 50 nm overall size, monodispersed, free of necking, single core iron oxide–SiO2 shell nanoparticles with tuneable shell thickness by a carefully optimized inverse microemulsion method. The high degree of control over the process is achieved by understanding the mechanism of core–shell nanoparticles formation. By varying the reaction time and precursor concentration, the thickness of silica layer on the core nanoparticles can be finely adjusted from 5 to 13 nm. Residual reactions during the workup were inhibited by a combination of pH control with shock freezing and ultracentrifuging. These high-quality tuneable core–shell nanocomposite particles exhibit superparamagnetic character and sufficiently high magnetization with great potential for biomedical applications (e.g. MRI, cell separation and magnetically driven drug delivery systems) either as-prepared or by additional surface modification for improved biocompatibility.  相似文献   

15.
We developed a simple and novel approach for the synthesis of Fe3O4@SiO2 nanoparticles with controlled shell thickness, and studied the mechanism. The introduction of N-methyl-2-pyrrolidone (NMP) led to trapping of monomer nuclei in single shell and controlled the shell thickness. Fe3O4@SiO2 controlled the shell thickness, showing a high magnetization value (64.47 emu/g). Our results reveal the role and change in the chemical structure of NMP during the core-shell synthesis process. NMP decomposed to 4-aminobutanoic acid in alkaline condition and decreased the hydrolysis rate of the silica coating process.  相似文献   

16.
可循环表面增强拉曼光谱基底的制备及其应用   总被引:1,自引:0,他引:1  
以氨基硅烷为偶联剂,硅酸钠为硅源,合成了一种以金为核,二氧化硅为壳的核壳纳米粒子。通过调节硅酸钠的量,反应温度和反应时间控制二氧化硅壳层厚度,获得理想的表面增强效应。通过研究表面增强拉曼光谱(SERS)信号强度和二氧化硅层厚度之间的关系优化基底的制备条件。采用对巯基苯和联吡啶作为探针分子进行SERS实验,在一定浓度范围内得到SERS信号强度和浓度的对数之间的线性关系,实验结果表明此组装有Au@SiO2的ITO基底作为可循环利用基底可定量分析吸附物种的浓度。  相似文献   

17.
The biological response to four well-characterized amorphous silica nanoparticles was investigated in RAW 264.7 macrophages in view of their potential application as drug carriers to sites of inflammation. All silica nanoparticles-induced cell membrane damage, reduced metabolic activity, generated ROS and released various cytokines, but to different extents. Two silica nanoparticles of 34 nm (A and B) with different zetapotentials were more cytotoxic than (aggregated) 11 and 248 nm nanoparticles, while cytokines were mostly induced by the (aggregated) 11 nm and only one of the 34 nm nanoparticles (34A). The results indicate that specific silica nanoparticles may have counterproductive effects, for example when used as carriers of anti-inflammatory drugs. The physicochemical properties determining the response of nanoparticles vary for different responses, implying that a screening approach for the safe development of nanoparticles needs to consider the role of combinations of (dynamic) physicochemical properties and needs to include multiple toxicity endpoints.  相似文献   

18.
The development of anticancer drug delivery systems based on biodegradable nanoparticles has been intended to maximize the localization of chemotherapy agents within tumor interstitium, along with negligible drug distribution into healthy tissues. Interestingly, passive and active drug targeting strategies to cancer have led to improved nanomedicines with great tumor specificity and efficient chemotherapy effect. One of the most promising areas in the formulation of such nanoplatforms is the engineering of magnetically responsive nanoparticles. In this way, we have followed a chemical modification method for the synthesis of magnetite/chitosan-l-glutamic acid (core/shell) nanostructures. These magnetic nanocomposites (average size ≈340 nm) exhibited multifunctional properties based on its capability to load the antitumor drug doxorubicin (along with an adequate sustained release) and its potential for hyperthermia applications. Compared to drug surface adsorption, doxorubicin entrapment into the nanocomposites matrix yielded a higher drug loading and a slower drug release profile. Heating characteristics of the magnetic nanocomposites were investigated in a high-frequency alternating magnetic gradient: a stable maximum temperature of 46 °C was successfully achieved within 40 min. To our knowledge, this is the first time that such kind of stimuli-sensitive nanoformulation with very important properties (i.e., magnetic targeting capabilities, hyperthermia, high drug loading, and little burst drug release) has been formulated for combined antitumor therapy against cancer.  相似文献   

19.
Daunting challenges in investigating the controlled release of drugs in complicated intracellular microenvironments demand the development of stimuli‐responsive drug delivery systems. Here, a nanoparticle system, CaF2:Tm,Yb@mSiO2, made of a mesoporous silica (mSiO2) nanosphere with CaF2:Tm,Yb upconversion nanoparticles (UCNPs) is developed, filling its mesopores and with its surface‐modified with polyacrylic acid for binding the anticancer drug molecules (doxorubicin, DOX). The unique design of CaF2:Tm,Yb@mSiO2 enables us to trigger the drug release by two mechanisms. One is the pH‐triggered mechanism, where drug molecules are preferentially released from the nanoparticles at acidic conditions unique for the intracellular environment of cancer cells compared to normal cells. Another is the 808 nm near infrared (NIR)‐triggered mechanism, where 808 nm NIR induces the heating of the nanoparticles to weaken the electrostatic interaction between drug molecules and nanoparticles. In addition, luminescence resonance energy transfer occurs from the UCNPs (the energy donor) to the DOX drug (the energy acceptor) in the presence of 980 nm NIR irradiation, allowing us to monitor the drug release by detecting the vanishing blue emission from the UCNPs. This study demonstrates a new multifunctional nanosystem for dual‐triggered and optically monitored drug delivery, which will facilitate the rational design of personalized cancer therapy.  相似文献   

20.
The aim of this study was to prepare a novel targeting nano drug delivery system of 2-methoxyestradiol (2-ME) based on the folic acid-modified bovine serum albumin, in order to improve the clinical application disadvantages and antitumor effect of 2-ME. In this study, 2-methoxyestradiol-loaded albumin nanoparticles (2-ME-BSANPs) were prepared by desolvation method, and then the activated folic acid was conjugated to 2-ME-BSANPs by covalent attachment (2-ME-FA-BSANPs). The size and zeta potential of 2-ME-FA-BSANPs were about 208.8 ± 5.1 nm and ?32.70 ± 1.01 mV, respectively. 2-ME loading efficiency and loading amount of the nanoparticles were 80.49 ± 3.80 and 10.25 ± 1.59 %, respectively. SEM images indicated that 2-ME-FA-BSANPs were of a round shape, similar uniform size, and smooth surface. Studies on drug release indicated that 2-ME-FA-BSANPs had the properties of sustained and controlled release, which provided them with the ability to fight continually against cancer cells. Internalization analysis demonstrated that 2-ME-FA-BSANPs-targeting drug delivery system could get efficiently transferred into the cells through the folic acid-mediated endocytosis, leading to higher apoptosis and affording higher antitumor efficacy against SMMC-7721 cells in vitro compared with 2-ME alone. Furthermore, the cell-cycle arrest of 2-ME-FA-BSANPs on the SMMC-7721 cells occurred at G2/M phase, and 2-ME-FA-BSANPs did not change the inhibition of the tumor mechanisms of 2-ME. Based on these results, it was concluded that albumin nanoparticles could be the promising nano carrier for 2-ME, and 2-ME-FA-BSANPs-targeting drug delivery system may be promising candidate for providing high treatment efficacy with minimal side effects in future cancer therapy.  相似文献   

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