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1.
Hollow magnetic nanoparticles (MNPs) with tetrahedral morphology were synthesized and then covered by a shell prepared by coating with melamine–formaldehyde followed by the introduction of glucose‐derived carbon. Subsequently, Pd nanoparticles were immobilized and the core–shell nanocomposite was carbonized. The obtained magnetic catalyst was successfully applied for the hydrogenation of nitroarenes in aqueous media. To investigate the effects of the morphology of MNPs, the nature of carbon shell, and the order of incorporation of Pd nanoparticles, several control catalysts, including the MNPs with different morphologies (disc‐like and cylinder); MNPs coated with different shells (sole glucose‐derived carbon or melamine–formaldehyde carbon shell); and a nanocomposite, in which Pd was immobilized after carbonization, were prepared and examined as catalyst for the model reaction. To justify the observed different catalytic activities of the catalysts, their Pd loadings, leaching, and specific surface areas were compared. The results confirmed that tetrahedral MNPs coated with porous N‐rich carbon shell exhibited the best catalytic activity. The high catalytic activity of this catalyst was attributed to its high surface area and the interaction of N‐rich shell with Pd nanoparticles that led to the higher Pd loading and suppressed Pd leaching.  相似文献   

2.
Cancer-based magnetic theranostics has gained significant interest in recent years and can contribute as an influential archetype in the effective treatment of cancer. Owing to their excellent biocompatibility, minute sizes and reactive functional surface groups, magnetic nanoparticles (MNPs) are being explored as potential drug delivery systems. In this study, MgFe2O4 ferrite MNPs were evaluated for their potential to augment the delivery of the anticancer drug doxorubicin (DOX). These MNPs were successfully synthesized by the glycol-thermal method and functionalized with the polymers; chitosan (CHI), polyvinyl alcohol (PVA) and polyethylene glycol (PEG), respectively, as confirmed by Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) confirmed the formation of the single-phase cubic spinel structures while vibrating sample magnetometer (VSM) analysis confirmed the superparamagnetic properties of all MNPs. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) revealed small, compact structures with good colloidal stability. CHI-MNPs had the highest DOX encapsulation (84.28%), with the PVA-MNPs recording the lowest encapsulation efficiency (59.49%). The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) cytotoxicity assays conducted in the human embryonic kidney (HEK293), colorectal adenocarcinoma (Caco-2), and breast adenocarcinoma (SKBR-3) cell lines showed that all the drug-free polymerized MNPs promoted cell survival, while the DOX loaded MNPs significantly reduced cell viability in a dose-dependent manner. The DOX-CHI-MNPs possessed superior anticancer activity (<40% cell viability), with approximately 85.86% of the drug released after 72 h in a pH-responsive manner. These MNPs have shown good potential in enhancing drug delivery, thus warranting further optimizations and investigations.  相似文献   

3.
Recyclable phase transfer catalysts containing magnetic nanoparticles (MNPs) have been known as a major trend towards sustainable catalysts. In this study, a novel class of magnetic porous polymer on the basis of calix[4]resorcinarene was synthesized starting from silica‐coated Fe3O4 core‐shell nanoparticles. This compound was found as an efficient phase transfer catalyst to the conversion of benzyl halides into benzyl azides and cyanides in good yields. The catalyst could be used at least for five consecutive cycles without appreciable loss in the catalytic activity.  相似文献   

4.
In recent years, gold nanoparticles (Au‐NPs) have been taken into consideration in nanomedicine due to their excellent biocompatibility, chemical stability and promising optical properties. In this research, podophyllotoxin conjugated with gold nanoparticles (Au‐NPs‐POT) was synthesized and the conjugation of POT with Au‐NPs was confirmed using scanning electron microscopy, mass spectrometry and Fourier transform infrared spectroscopy. The anticancer effects of the product on preclinical models of lung, colon and breast cancers were investigated using MTT test. The analyses showed a direct dose–response relationship. It was found that higher concentrations of POT have more positive effects on the inhibition of cancer cell growth. At POT concentrations of 1, 2.5, 5, 7.5, 10, 15 and 20 ng ml?1, approximately 50% of the growth of colorectal, lung and breast cancer cell lines was inhibited, while similar results were obtained in the presence of 1, 2, 3, 4 and 5 μg ml?1 Au‐NPs‐POT. Au‐NPs‐POT exhibited the lowest cytotoxicity due to the presence of POT. The anticancer feature of Au‐NPs‐POT proved the potential to develop better anticancer therapeutics and to open new avenues for treatment of cancers.  相似文献   

5.
In current nanoscience bioengineered magnetic nanoparticles (NPs) have come into prominence with considerable impact. These advanced functional materials find outstanding applications in chemical science in catalysis, environmental issues, sensing etc, as well as in biology as drug delivery agent, chemical therapeutics and others. We have been prompted to architect and synthesize a novel Au NP adorned over chitosan-biguanidine polyplex modified core–shell type magnetic nanocomposite (Fe3O4/CS-biguanidine/Au NPs). The bioshells facilitate to protect the core ferrite NPs as well as provides stability to the synthesized Au NPs by capping. The material was characterized using different analytical techniques like Fourier Transformed Infra-Red spectroscopy (FT-IR), Inductively Coupled Plasma-Optical Emission Microscopy (ICP-OES), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM) and X-ray Diffraction (XRD) studies. We explored the biological application of the nanocomposite in determining cytotoxicity of three adenocarcinoma cell lines (PC-14, LC-2/ad, HLC-1) through the MTT assay. The material showed very good activity by exhibiting very low % cell viability over the cell lines dose-dependently. The IC50 of Fe3O4/CS-biguanidine/Au NPs were observed 503, 398 and 475 µg/mL respectively against the three cell lines. The best output was observed at a concentration of 1000 µg/mL of catalyst in terms of cytotoxicity and inhibition of lung cancer growth. The anti-cancer potential was found in close relation to their antioxidant potential.  相似文献   

6.
Herein, we report the synthesis of biocompatible triplex Ag@SiO2@mTiO2 core–shell nanoparticles (NPs) for simultaneous fluorescence‐surface‐enhanced Raman scattering (F‐SERS) bimodal imaging and drug delivery. Stable Raman signals were created by typical SERS tags that were composed of Ag NPs for optical enhancement, a reporter molecule of 4‐mercaptopyridine (4‐Mpy) for a spectroscopic signature, and a silica shell for protection. A further coating of mesoporous titania (mTiO2) on the SERS tags offered high loading capacity for a fluorescence dye (flavin mononucleotide) and an anti‐cancer drug (doxorubicin (DOX)), thereby endowing the material with fluorescence‐imaging and therapeutic functions. The as‐prepared F‐SERS dots exhibited strong fluorescence when excited by light at 460 nm whilst a stable, characteristic 4‐Mpy SERS signal was detected when the excitation wavelength was changed to longer wavelength (632.8 nm), both in solution and after incorporation inside living cells. Their excellent biocompatibility was demonstrated by low cytotoxicity against MCF‐7 cells, even at a high concentration of 100 μg mL?1. In vitro cell cytotoxicity confirmed that DOX‐loaded F‐SERS dots had a comparable or even greater therapeutic effect compared with the free drug, owing to the increased cell‐uptake, which was attributed to the possible endocytosis mechanism of the NPs. To the best of our knowledge, this is the first proof‐of‐concept investigation on a multifunctional nanomedicine that possessed a combined capacity for fast and multiplexed F‐SERS labeling as well as drug‐loading for cancer therapy.  相似文献   

7.
《Mendeleev Communications》2023,33(3):340-342
Internalization of poloxamer 188-coated PLGA nanoparticles (NPs) in GL261 murine glioma cells was studied using confocal laser scanning microscopy. For visualization, both poloxamer 188 (P188) and PLGA were labeled covalently with fluorescent dyes Rhodamine B and Cyanine5, respectively. The results indicated that the PLGA NPs coated with poloxamer 188 enter a cell as an integral core–shell structure, which can be helpful for gaining further insight into the in vivo performance of surfactant-coated polymeric NPs as core–shell delivery systems  相似文献   

8.
Well‐defined, core‐shell poly(methyl methacrylate) (PMMA)/casein nanoparticles, ranging from 80 to 130 nm in diameter, were prepared via a direct graft copolymerization of methyl methacrylate (MMA) from casein. The polymerization was induced by a small amount of alkyl hydroperoxide (ROOH) in water at 80 °C. Free radicals on the amino groups of casein and alkoxy radicals were generated concurrently, which initiated the graft copolymerization and homopolymerization of MMA, respectively. The presence of casein micelles promoted the emulsion polymerization of the monomer and provided particle stability. The conversion and grafting efficiency of the monomer strongly depended on the type of radical initiator, ROOH concentration, casein to MMA ratio, and reaction temperature. The graft copolymers and homopolymer of PMMA were isolated and characterized with Fourier transform infrared spectroscopy and differential scanning calorimetry. The molecular weight determination of both the grafted and homopolymer of PMMA suggested that the graft copolymerization and homopolymerization of MMA proceeded at a similar rate. The transmission electron microscopic image of the nanoparticles clearly showed a well‐defined core‐shell morphology, where PMMA cores were coated with casein shells. The casein shells were further confirmed with a zeta‐potential measurement. Finally, this synthetic method allowed us to prepare PMMA/casein nanoparticles with a solid content of up to 31%. Thus, our new process is commercially viable. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3346–3353, 2003  相似文献   

9.
Plasmonic Au and magnetic Fe are coupled into uniform Au@Fe core–shell nanoparticles (NPs) to confirm that electron transfer occurred from the Au core to the Fe shell. Au NPs synthesized in aqueous medium are used as seeds and coated with an Fe shell. The resulting Au@Fe NPs are characterized by using various analytical techniques. X‐ray photoelectron spectroscopy and superconducting quantum interference device measurements reveal that the Fe shell of the Au@Fe NPs mainly consists of paramagnetic Wüstite with a thin surface oxide layer consisting of maghemite or magnetite. Electron transfer from the Au core to the Fe shell effectively suppresses iron oxidation from Fe2+ to Fe3+ near the interface between the Au and the Fe. The charge‐transfer‐induced electronic modification technique enables us to control the degree of iron oxidation and the resulting magnetic properties.  相似文献   

10.
Affinity core‐shell magnetic nanoparticles (MNPs) were prepared for identifying the target proteins of drugs in the cell lysate when used in combination with nano‐high‐performance liquid chromatography tandem mass spectrometry (HPLC‐MS/MS)‐based shotgun proteomic analysis. A number of new potential targets of cyclosporine A (CsA) could be identified, owing to the high efficacy of the affinity MNPs in drug target identification. To the best of our knowledge, this is the first time to reveal such an abundant target spectrum of CsA.  相似文献   

11.
Cancer remains a leading cause of death worldwide, despite extraordinary progress. So, new cancer treatment modalities are needed. Tumor-treating fields (TTFs) use low-intensity, intermediate-frequency alternating electric fields with reported cancer anti-mitotic properties. Moreover, nanomedicine is a promising therapy option for cancer. Numerous cancer types have been treated with nanoparticles, but zinc oxide nanoparticles (ZnO NPs) exhibit biocompatibility. Here, we investigate the activity of TTFs, a sub-lethal dose of ZnO NPs, and their combination on hepatocellular carcinoma (HepG2), the colorectal cancer cell line (HT-29), and breast cancer cell lines (MCF-7). The lethal effect of different ZnO NPs concentrations was assessed by sulforhodamine B sodium salt assay (SRB). The cell death percent was determined by flow cytometer, the genotoxicity was evaluated by comet assay, and the total antioxidant capacity was chemically measured. Our results show that TTFs alone cause cell death of 14, 8, and 17% of HepG2, HT-29, and MCF-7, respectively; 10 µg/mL ZnO NPs was the sub-lethal dose according to SRB results. The combination between TTFs and sub-lethal ZnO NPs increased the cell death to 29, 20, and 33% for HepG2, HT-29, and MCF-7, respectively, without reactive oxygen species increase. Increasing NPs potency using TTFs can be a novel technique in many biomedical applications.  相似文献   

12.
In this article, magnetite nanoparticles (MNPs) coated with glycopolymer bearing glucose moieties were designed with optimal structural, colloidal, and magnetic properties for biomedical applications. MNPs with an average size of 17 ± 2 nm were synthesized by thermal decomposition process and then their surfaces were modified with active vinyl groups. Two different monomers were immobilized onto the surfaces: dopamine methacrylamide, a monomer with properties inspired on mussels adhesive capacity, or unprotected glycomonomer, 2‐{[(D ‐glucosamin‐2N‐yl)carbonyl]‐oxy}ethyl methacrylate. Afterward, the glycomonomer were polymerized at the interface of both vinyl functionalized MNPs by conventional radical polymerization. The resultant hybrid NPs were water dispersible presenting good stability in aqueous solution for long time periods. Moreover, the high density of carbohydrates at the surface of the magnetic NPs could confer targeting properties to the system as demonstrated by studies of their binding interactions with lectins, where the binding activity is higher as the glycopolymer content augments. The magnetic and magneto‐thermal properties of the synthesized hybrid NPs were evaluated. The magnetization curves reveal superparamagnetic features at 300 K, with high values of saturation magnetization. Furthermore, the hybrid glycoparticles show suitable heat dissipation power when exposed to alternating magnetic field conditions. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

13.
Immune cell engineering is an active field of ongoing research that can be easily applied to nanoscale biomedicine as an alternative to overcoming limitations of nanoparticles. Cell membrane coating and artificial nanovesicle technology have been reported as representative methods with an advantage of good biocompatibility for biomimetic replication of cell membrane characteristics. Cell membrane-mediated biomimetic technique provides properties of natural cell membrane and enables membrane-associated cellular/molecular signaling. Thus, coated nanoparitlces (NPs) and artificial nanovesicles can achieve effective and extended in vivo circulation, enabling execution of target functions. While coated NPs and artificial nanovesicles provide clear advantages, much work remains before clinical application. In this review, first a comprehensive overview of cell membrane coating techniques and artificial nanovesicles is provided. Next, the function and application of various immune cell membrane types are summarized.  相似文献   

14.
设计制备了一种新型微孔介孔复合核壳结构钛硅分子筛TS-1@Mesosilica(TS-l@Ms),核为MFI结构钛硅分子筛TS-1,壳层为以非离子表面活性剂P123为模板剂组装形成的介孔氧化硅.壳层氧化硅具有三维蠕虫状孔道结构,有利于微孔和介孔部分的连通及反应物和产物的扩散.通过沉积沉淀法将金纳米粒子负载在壳层介孔孔道,和TS-1中的钛活性中心协同,形成适合于C3H6和H2、O2直接气相环氧化制备环氧丙烷(PO)的双功能催化材料.实验结果表明,Au/TS-1@MS在空速8000mLg-h、温度473K条件下连续反应132h,活性和选择性没有明显下降,丙烯转化率保持在3.7%左右,PO选择性87%以上.  相似文献   

15.
This paper demonstrates that capillary electrophoresis (CE) can be employed for characterizing the sizes of a series of Au/Ag core/shell nanoparticles (NPs). We effected the CE separation of Au/Ag core/shell NPs using a mixed buffer of sodium dodecyl sulphate (SDS) (40 mM) and 3-(cyclohexylamino)propanesulfonic acid (10 mM) at pH 9.7 and an applied voltage of 20 kV. A linear relationship (R(2)>0.99) existed between the electrophoretic mobilities and the sizes of the Au/Ag core/shell NPs within the diameter range from 25 to 90 nm; the relative standard deviations of these electrophoretic mobilities were <0.9%. From the good correlation between the results obtained by CE and those provided by scanning electron microscopy, we confirmed that this CE method is a valid one for characterizing the sizes of Au/Ag core/shell NP samples. In addition, when the Au/Ag core/shell NPs were separated through CE and detected using an on-line photodiode array detector, this approach allowed the chemical characterization of the NP species. This CE approach should allow the rapid and cost-effective characterization of a number of future nanomaterials.  相似文献   

16.
This article displays synthesis of Silver nanoparticles (Ag NPs) decorated on sodium alginate covered magnetite (Fe3O4/Alg-Ag NPs) nanocomposite. Sodium alginate shell as a natural anionic polysaccharide on Fe3O4 microparticles core acted as a stabilizing agent for the reduction of Ag(I) ions into Ag NPs. The structural features of the synthesized nanocomposite were investigated by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopes (FE-SEM), transmission electron microscopes (TEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating-sample magnetometer (VSM) studies and inductively coupled plasma-optical emission spectroscopy (ICP-OES). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used on common lung cancer cell lines i.e., NCI-H1975, NCI-H1563, and NCI-H1299 to survey the cytotoxicity and anti-lung cancer effects of the synthesized nanocomposite. The synthesized nanocomposite had very low cell viability and high anti-lung cancer activities dose-dependently against NCI-H1975, NCI-H1563, and NCI-H1299 cell lines without any cytotoxicity on the normal cell line (Human umbilical vein endothelial cells (HUVECs)). To determine the antioxidant properties of the synthesized nanocomposite, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used in the presence of butylated hydroxytoluene as the positive control. The synthesized nanocomposite inhibited half of the DPPH molecules in the concentration of 194 µg/mL. Maybe significant anti-human lung cancer potentials of the synthesized nanocomposite against common human lung cancer cell lines are linked to their antioxidant activities.  相似文献   

17.
A new method is applied to prepare stable aqueous dispersion of magnetic iron oxide nanoparticles (MNPs) by biocompatible maleate polymers. Fe3O4 magnetic core–shell nanoparticles are obtained via forming an inclusion complex between carboxylic acid groups of maleated biocompatible polymers shell and Fe3O4 MNPs core surface. Maleate polymers are synthesized via esterification of poly(ethylene glycol), poly(vinyl alcohol) and starch with maleic anhydride (MA). The Fe3O4 magnetic core–shell nanoparticles are characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The obtained magnetic core–shell nanoparticles exhibit superparamagnetic property and reveal long‐term aqueous stability. This work represents a valid methodology to produce highly stable aqueous dispersion of Fe3O4 MNPs ferrofluids which can be expected to have great potential as contrast agent for magnetic resonance imaging. Furthermore, the shell composition of biocompatible maleate polymers with double bond of MA as crosslinker agent allows the polymerization with other monomers to design preferred drug delivery systems. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

18.
Advances in chemical syntheses have led to the formation of various kinds of nanoparticles (NPs) with more rational control of size, shape, composition, structure and catalysis. This review highlights recent efforts in the development of Pt and non‐Pt based NPs into advanced nanocatalysts for efficient oxygen reduction reaction (ORR) under fuel‐cell reaction conditions. It first outlines the shape controlled synthesis of Pt NPs and their shape‐dependent ORR. Then it summarizes the studies of alloy and core–shell NPs with controlled electronic (alloying) and strain (geometric) effects for tuning ORR catalysis. It further provides a brief overview of ORR catalytic enhancement with Pt‐based NPs supported on graphene and coated with an ionic liquid. The review finally introduces some non‐Pt NPs as a new generation of catalysts for ORR. The reported new syntheses with NP parameter‐tuning capability should pave the way for future development of highly efficient catalysts for applications in fuel cells, metal‐air batteries, and even in other important chemical reactions.  相似文献   

19.
Drug targeting using magnetic nanoparticles (MNPs) under the action of an external magnetic field constitutes an important mode of drug delivery. Low cargo capacity, particularly in hydrophobic drugs, is one limitation shown by MNPs. This article describes a simple strategy to enhance the drug-loading capacity of MNPs. The approach was to use polymer-drug conjugates to modify MNPs by layer-by-layer assembly (LbL). Curcumin (CUR) has shown remarkably high cytotoxicity toward various cancer cell lines. However, the drug shows low anticancer activity in vivo because of its reduced systemic bioavailability acquired from its poor aqueous solubility and instability. To address this issue, we synthesized cationic and anionic CUR conjugates by anchoring CUR onto poly(vinylpyrroidone) (PVP-Cur) and onto hyaluronic acid (HA-Cur). We used these oppositely charged conjugates to modify MNPs by layer-by-layer (LbL) assembly. Six double layers of curcumin conjugates were constructed on positively charged amino-terminated magnetic nanoparticles, TMSPEDA@MNPs. Finally, HA was coated onto the outer surface to form HA (HA-Cur/PVP-Cur)(6)@MNPs. Cellular viability studies showed the dose-dependent antiproliferative effect of HA (HA-Cur/PVP-Cur)(6)@MNPs in two cancer cell lines (glioma cells and Caco-2 cells). HA (HA-Cur/PVP-Cur)(6)@MNPs exhibited more cytotoxicity than did free curcumin, which was attributed to the enhanced solubility along with better absorption via hyaluronic acid receptor-mediated endocytosis. Flow cytometry showed enhanced intake of the modified MNPs by cells. Confocal microscope images also confirmed the uptake of HA (HA-Cur/PVP-Cur)(6)@MNPs with greater efficacy. Thus, the strategy that we adopted here appears to have substantial potential in carrying enhanced payloads of hydrophobic drugs to specified targets.  相似文献   

20.
Nanoparticles (NPs) exhibit interesting size-dependent electrical, optical, magnetic, and chemical properties that cannot be observed in their bulk counterparts. The synthesis of NPs (i.e., crystalline particles ranging in size from 1 to 100 nm) has been intensely studied in the past decades. Magnetic nanoparticles (MNPs) form a particularly attractive class of NPs and have found numerous applications such as in magnetic resonance imaging to visualize cancer, cardiovascular, neurological and other diseases. Other uses include drug targeting, tissue imaging, magnetic immobilization, hyperthermia, and magnetic resonance imaging. MNPs, due to their magnetic properties, can be easily separated from (often complex) matrices and manipulated by applying external magnetic field. Near-infrared to visible upconversion luminescent nanoparticles (UCLNPs) form another type of unusual nanoparticles. They are capable of emitting visible light upon NIR light excitation. Lanthanide-doped (Yb, Er) hexagonal NaYF? UCLNPs are the most efficient upconversion phosphors known up to now. The use of UCLNPs for in vitro imaging of cancer cells and in vivo imaging in tissues has been demonstrated. UCLNPs show great potential as a new class of luminophores for biological, biomedical, and sensor applications. We are reporting here on our first results on the combination of MNP and UCLNP technology within an ongoing project supported by the DFG and the FWF (Austria).  相似文献   

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