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1.
合成一种具有pH响应性的聚乙二醇(PEG)修饰无定形介孔氧化铁纳米粒子(AFe-PEG).这种纳米粒子可以高效负载药物分子如阿霉素(DOX),构成新型多功能AFe-PEG/DOX药物递送体系.DOX的负载率高达948 mg/g-纳米粒子.在酸性溶液中,AFePEG/DOX纳米粒子不仅可以有效释放DOX,同时可以释放Fe离子进行Fenton反应,将H_2 O_2转变成·OH自由基.体外实验结果表明,AFe-PEG/DOX纳米粒子对HeLa细胞同时具有化疗和化学动力学疗法的疗效.同时,由于AFe-PEG/DOX纳米粒子本身的磁性,使其在外部磁场中的细胞内化效率也得到了提高.  相似文献   

2.
制备了负载抗癌药物阿霉素(DOX)并且具有表面增强拉曼散射(SERS)响应和荧光响应的复合纳米粒子。SERS成像和荧光成像结果表明纳米粒子可以成功被人结肠癌细胞(HT-29)内吞,并且DOX可以在细胞中释放。复合纳米粒子外层聚乙烯亚胺(PEI)膜层结构具有pH响应,可以加大DOX在不同pH环境的释放差异,达到药物控制释放的目的。这种复合纳米粒子模型在细胞成像、肿瘤药物研发等领域具有潜在应用价值。  相似文献   

3.
通过种子乳液聚合合成核壳结构的聚甲基丙烯酸甲酯/聚苯乙烯(PMMA/PS)复合微球,通过酸碱溶胀法进一步制备出次微米级的PS中空微球. 将此中空微球作为微反应器,使在ZnO纳米粒子前驱体溶液中溶胀, 最终ZnO纳米粒子在PS中空微球中原位生成. 实验表明, 组成ZnO纳米粒子前驱体溶液的两种组 分(CH3COO)2Zn和LiOH的滴加顺序不同对最终生成的ZnO纳米粒子的尺寸和负载效率有很大的影响,但并不改变ZnO纳米粒子的晶型. 复合物的光致发光和UV-Vis吸  相似文献   

4.
通过水解TiCl4制备了锐钛矿结构TiO2纳米粒子, 并用时间分辨荧光光谱研究了5(6)CFL(5(6)-Carboxyfluorescein, 简称5(6)CFL)染料敏化TiO2纳米粒子体系的光致电子转移动力学. 5(6)CFL染料敏化TiO2纳米粒子能形成电荷转移复合物, 这归因于染料分子的激发电子态波函数Ψ(D*)与电荷分离态波函数Ψ(D+ +e-)之间的耦合作用. 当激发5(6)CFL染料敏化TiO2纳米粒子体系时, 电子以两种不同方式注入TiO2纳米粒子导带: 第一, 通过5(6)CFL染料分子的激发态注入; 第二, 从电荷转移复合物(5(6)CFL/TiO2)直接注入. 时间分辨荧光光谱表明, 在水溶液中纯5(6)CFL染料的荧光以寿命为τ1=41 ps (74.4%) 和τ2=3.22 ns (25.6%) 的双e指数衰减, 而5(6)CFL染料敏化TiO2纳米粒子体系的荧光分别以时间常数为τ1=44 ps (90.4%), τ2=478 ps (8.6%) 和τ3=2.41 ns (1.0%) 的三e指数衰减. 本文的研究工作能够为染料敏化太阳能电池的光致电子转移机理提供有价值的参考.  相似文献   

5.
采用计时电流法制备了负载Zn纳米粒子的TiO2纳米管阵列电极.通过阳极氧化法制备TiO2纳米管阵列电极,然后通过控制计时电流沉积时间来控制负载在TiO2纳米管上Zn纳米颗粒的沉积量和 沉积尺寸.SEM和XRD分析结果显示,沉积时间为3~5 s时,负载在TiO2纳米管上的Zn粒子的直径为15~25 nm.UV漫反射光谱发现负载Zn的TiO2纳米管阵列电极比没有负载的样品吸收487~780 nm的光更强;在高压汞灯照射下,前者比后者的光电流响应提高了50%.  相似文献   

6.
本文通过一个简单的、温和的方案制备了平均尺寸为120 nm,介孔结构的纳米粒子MnSiO3@Fe3O4@C. 粒子的细胞毒性微小,可以用作T1-T2*双模MRI造影剂. 酸性条件下MnSiO3@Fe3O4@C释放出大量的Mn2+缩短T1弛豫时间,提高成像分辨率. 超顺磁性的Fe3O4可以增强T2对比成像,检测病变组织. 类似于肿瘤微环境/细胞器的酸性PBS(pH=5.0)中Mn2+的释放率达到31.66%,约为中性条件(pH=7.4)下的7倍. 释放的Mn2+通过内吞作用被细胞摄取,经肾脏排出,细胞毒性实验表明,MnSiO3@Fe3O4@C具有低的细胞毒性,即使高浓度的200 ppm MnSiO3@Fe3O4@C对HeLa细胞的毒性也相对较小. 对荷瘤小鼠静脉注射定量MnSiO3@Fe3O4@C后,可以观察到一个快速增强的对比成像,给药24 h后,T1MRI信号显著增强,达到132%,而T2信号则明显降低至53.8%,活体MR成像证明了MnSiO3@Fe3O4@C可以同时作为阳性和阴性造影剂. 此外,得益于介孔MnSiO3优秀的酸敏感性,MnSiO3@Fe3O4@C可以作为一种潜在的药物载体,实现肿瘤的诊疗一体化.  相似文献   

7.
李冬冬  王丽莉 《物理学报》2012,61(3):34212-034212
首次用二氧化钛(TiO2)纳米材料修饰的547孔微结构聚合物光纤(MPOF)二次预制棒作为阵列化微管式光催化反应器对亚甲基兰的光催化分解进行研究.将高光催化活性的P25型二氧化钛纳米粒子均匀分散在TiO2溶胶中,对547孔微结构聚合物光纤孔洞内壁进行铺膜,得到了负载光催化剂的阵列化微管材料.该TiO2MPOF有序复合的阵列化微管不仅对二氧化钛纳米粒子起到负载作用,还可以作为光波导介质(rolling-up薄膜波导,聚光、导光进入二氧化钛薄膜层)、污染物反应流体通道.以有机染料亚甲基兰为模拟污染物,研究了TiO2负载量、亚甲基兰的初始浓度及溶液pH值等因素对光降解效果的影响.该反应器547个孔道的内表面用于负载光催化剂,不仅增加了固-液接触面积,也提高了光的吸收效率,从而提高了光催化效率.迄今为止,这种兼具导光、聚光、传质、负载功能于一体的光催化反应器还未见报道.  相似文献   

8.
使用了一种具有较大通用性的方法制备了金属/二氧化钛(TiO2)核壳纳米结构. 采用电沉积方法在多孔氧化铝模板(AAO)孔洞中沉积壁厚均一的TiO2纳米管,TiO2纳米管的壁厚可以通过沉积时间来控制,而纳米管的直径和长度则由模板孔洞大小和模板厚度决定. 采用这种方法制备的TiO2纳米管顶端是开放的,而底端连接在电沉积前溅射在AAO模板背面的金膜上. 这种TiO2纳米管阵列结构适合进行二次电沉积,以它为模板将Pd、Cu、Fe等金属沉积到纳米管中形成核壳纳米棒结构. 这是一种可以用于制备多种金属/TiO2核壳纳米结构的通用方法,采用这种方法制备的金属/TiO2核壳纳米棒结构具有填充率高和取向性好的特点,而且它们的壁厚和长度可以通过分别改变两步电沉积的时间来控制.  相似文献   

9.
利用XPS和RPES技术研究了CeO2-x(111)薄膜表面上的氧空位对Ag纳米颗粒的生长和电子结构的影响. XPS结果表明,室温下,Ag纳米颗粒在部分还原的CeO2-x(111)薄膜上呈三维岛状生长, 并且岛密度比完全氧化的CeO2(111)薄膜表面上的大, 说明氧空位可以作为Ag纳米粒子生长的中心. Ag3d5/2芯能级的结合能随着Ag颗粒尺寸的减小而增大, 主要来源于终态效应的贡献. Ag和CeO2-x  相似文献   

10.
研究了通过有机金属化学气相沉积技术及单源分子前躯体方法制备的Ni/Al2O3纳米复合材料的氢吸附(存储). 在冷壁的有机金属化学气相沉积反应器中,通过降解Ni(acac)2粉末基底上的[H2Al(OtBu)]2制备的Ni/Al2O3纳米复合材料. 通过X射线粉末衍射、扫描电镜、透射电镜以及能量色散型X射线荧光光谱等技术表征该复合材料. 采用自制Sievert's设备研究该复合材料的氢吸附(存储),可以储存约2.9%(重量比)的氢.  相似文献   

11.
This detailed review presents an overview of current research on the synthesis, surface modification, and applications of Iron oxide (Fe3O4) nanoparticles and iron oxide/gold (Fe3O4/Au) nanocomposites. The different synthesis techniques of Fe3O4 with various basic organic and inorganic modifications are presented. The applicability and role of inorganic and organic coating on iron oxide/gold core/shell schemes were explored. The trade-off between choices for surface functionalization related to specific applications such as imaging contrast agent, drug delivery carrier and therapeutic device using iron oxide/gold core/shell was also elaborated. The versatility of combining iron oxide/ and gold as nanocomposite as the choice for biomedical application is demonstrated in MRI, CT scan, drug delivery, biosensors, and hyperthermia application.  相似文献   

12.
《Physics letters. A》2020,384(24):126600
This work was primarily focused on the synthesis, characterization and biomedical applications of cobalt ferrite (CoFe2O4) nanoparticles, which were synthesized by a facile solvothermal method using an amino acid of Leucine (Leu) as the surface coating agents. The morphology, structure and properties of the as-synthesized uncoated and Leu-coated CoFe2O4 nanoparticles were characterized in detail by means of XRD, SEM, TEM, DLS, FTIR, XPS, TGA and SQUID. More importantly, it was found that the Leu-coated CoFe2O4 nanoparticles can be used as the efficient drug delivery with a drug loading capacity of 0.32 mg/mg for doxorubicin hydrochloride (DOX), and the loaded DOX demonstrated a sustained and progressive release manner. The in vitro cytotoxicity studies towards the HeLa cells were carried out, and the results indicated that the Leu-coated CoFe2O4 nanoparticles exhibited a relatively high cell viability compared with that of bare CoFe2O4 nanoparticles and the DOX loaded Leu-coated CoFe2O4 nanoparticles presented an obvious cytotoxic effect on HeLa cells.  相似文献   

13.
《Current Applied Physics》2020,20(2):320-325
A facile method is developed for the fabrication of magnetic iron oxide nanoparticle-hollow mesoporous silica spheres (IONP-HMSs) and explored their potential application in drug delivery. Through the self-assembling process of IONPs and the formation of mesoporous silica shells, the IONP-HMSs with hollow interior cavity were obtained. The cetyltrimethyl ammonium bromide (CTAB) encapsulated IONP-containing spheres served as the template to establish the mesoporous silica shells. Typical anti-cancer drug, doxorubicin hydrochloride (DOX) was applied for drug loading and release process of IONP-HMSs, which demonstrated the IONP-HMSs have a high drug loading efficiency and allow pH-trigged release of DOX in vitro. Moreover, the IONP-HMSs exhibited excellent biocompatibility and enhanced DOX therapeutic efficacy to HeLa cells. Compared with traditional methods, the reported microemulsion-based method for the synthesis of IONP-HMSs enables the formation of hollow-structured nanocomposite without any complex template-removing process, which could pave the way to improving the therapeutic efficacy in drug delivery system.  相似文献   

14.
Chemodynamic therapy (CDT) is a promising method that uses endogenous hydrogen peroxide (H2O2) to produce cytotoxic hydroxyl radicals (•OH) via Fenton reaction to kill tumor cells. However, the insufficient contents of H2O2 and the presence of glutathione (GSH) can significantly reduce the therapeutic effect of CDT. Herein, a multifunctional nanoregulator (3-AT&MA@FHM) that combines Fe-doped hollow mesoporous silica nanoparticles (Fe-doped hMSN, or FHM) with 3-amino-1,2,4-triazole (3-AT) and maleimide (MA) are developed to overcome these challenges. After endocytosis by tumor cells, FHM part of the nanoregulator degrades in a mildly acidic intracellular environment and releases Fe3+ for CDT. The subsequently released 3-AT serves as a catalase inhibitor to promote the accumulation of H2O2, while MA acts as a GSH scavenger to decrease the GSH content in tumor cells. This multifunctional nanoplatform simultaneously regulates the contents of H2O2-the substrate for Fenton reaction and GSH-the main antioxidant, resulting in a significantly enhanced CDT effect. Moreover, organoids are used for safety and toxicity evaluation. The results of organoids experiments showed similar trends to those of cellular experiments, but MIO is more resistant to stress than cells. This study is expected to provide a novel idea for the design of highly efficient CDT nanosystems.  相似文献   

15.
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   

16.
A functionalization of iron oxide nanoparticles (NPs) of different diameters by the amphiphilic invertible polymer, (PEG600‐alt‐PTHF650)k (PEG and PTHF stand for poly(ethylene glycol) and poly(tetrahydrofuran), respectively), leads to different NP/polymer architectures for dye/drug uptake and release, as is reported here for the first time. It is demonstrated that 18.6 ± 1.4 and 11.9 ± 0.6 nm NPs are individually coated by this polymer, while 5.9 ± 0.6 nm NPs form nanoparticle clusters (NPCs) which could be isolated by either ultracentrifugation or magnetic separation. This phenomenon is most likely due to the character of the (PEG600‐alt‐PTHF650)k macromolecule with alternating hydrophilic and hydrophobic fragments and its dimensions sufficient to cause NP clustering. Utilizing Rhodamine B base (RBB) and doxorubicin (DOX), the data on uptake upon mixing and further release via inversion into octanol (mimicking the penetration of the cell biomembrane) are presented. The magnetic NPCs display enhanced uptake and release of both RBB and DOX most likely due to the higher retained polymer amount. The NPCs also display exceptional magnetic resonance imaging properties. This and the high uptake/release efficiency of the NPCs combined with easy magnetic separation make them promising for theranostic probes for magnetically targeted drug delivery.  相似文献   

17.
A strategy to incorporate and release the amphiphilic drugs of doxorubicin (DOX) and ibuprofen (IBU) in the same microcapsules is introduced, A layer-by-layer (LbL) assembly of microcapsules with doxorubicin hydrochloride (DOX) or green fluorescent agent, hydrophilic fluorescein isothiocyanate (FITC), encapsulated in CaCO3 microparticle templates, was conducted via alternatively depositing sodium carboxymethyl cellulose (CMC) and chitosan (CHI) onto IBU or red fluorescent agent (hydrophobic Nile Red) preloaded poly-L-lactide (PLLA) coated magnetic Fe3O4-DOX-loaded CaCO3 (or FITC-loaded) templates. The structure, morphology, composition, magnetic properties and drugs distribution of the obtained microcapsules were characterized by nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), zeta potential analysis, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM) and confocal laser scanning microscopy. The fluorescent agents loading of FITC and Nile Red were confirmed by observations using confocal laser scanning microscopy. Fluorescence observations showed that the DOX was distributed both in the walls and in the cavities of the microcapsules, while IBU was present in the capsule wall. The in–vitro release of the dual drugs, DOX and IBU, from the microcapsules with different numbers of CHI and CMC layers was characterized. A tunable amount of drug release was achieved by changing the number of layers. The release study indicated that the LBL microcapsules exhibited better sustained release capacity compared to the uncoated microcapsules. The microcapsules inherited a strong magnetic property from the Fe3O4 nanoparticles, sufficient for targeting and magnetic hyperthermia drug delivery systems.  相似文献   

18.
Superparamagnetic iron oxide nanoparticles are used in diverse applications, including optical magnetic recording, catalysts, gas sensors, targeted drug delivery, magnetic resonance imaging, and hyperthermic malignant cell therapy. Combustion synthesis of nanoparticles has significant advantages, including improved nanoparticle property control and commercial production rate capability with minimal post-processing. In the current study, superparamagnetic iron oxide nanoparticles were produced by flame synthesis using a coflow flame. The effect of flame configuration (diffusion and inverse diffusion), flame temperature, and additive loading on the final iron oxide nanoparticle morphology, elemental composition, and particle size were analyzed by transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), energy dispersive spectroscopy (EDS), and Raman spectroscopy. The synthesized nanoparticles were primarily composed of two well known forms of iron oxide, namely hematite αFe2O3 and magnetite Fe3O4. We found that the synthesized nanoparticles were smaller (6–12 nm) for an inverse diffusion flame as compared to a diffusion flame configuration (50–60 nm) when CH4, O2, Ar, and N2 gas flow rates were kept constant. In order to investigate the effect of flame temperature, CH4, O2, Ar gas flow rates were kept constant, and N2 gas was added as a coolant to the system. TEM analysis of iron oxide nanoparticles synthesized using an inverse diffusion flame configuration with N2 cooling demonstrated that particles no larger than 50–60 nm in diameter can be grown, indicating that nanoparticles did not coalesce in the cooler flame. Raman spectroscopy showed that these nanoparticles were primarily magnetite, as opposed to the primarily hematite nanoparticles produced in the hot flame configuration. In order to understand the effect of additive loading on iron oxide nanoparticle morphology, an Ar stream carrying titanium-tetra-isopropoxide (TTIP) was flowed through the outer annulus along with the CH4 in the inverse diffusion flame configuration. When particles were synthesized in the presence of the TTIP additive, larger monodispersed individual particles (50–90 nm) were synthesized as observed by TEM. In this article, we show that iron oxide nanoparticles of varied morphology, composition, and size can be synthesized and controlled by varying flame configuration, flame temperature, and additive loading.  相似文献   

19.
The potential for using hydroxyl radical (OH?) reactions catalyzed by iron oxide nanoparticles (NPs) to remediate toxic organic compounds was investigated. Iron oxide NPs were synthesized by controlled oxidation of iron NPs prior to their use for contaminant oxidation (by H2O2 addition) at near-neutral pH values. Cross-linked polyacrylic acid (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes were prepared by in situ polymerization of acrylic acid inside the membrane pores. Iron and iron oxide NPs (80–100 nm) were directly synthesized in the polymer matrix of PAA/PVDF membranes, which prevented the agglomeration of particles and controlled the particle size. The conversion of iron to iron oxide in aqueous solution with air oxidation was studied based on X-ray diffraction, Mössbauer spectroscopy and BET surface area test methods. Trichloroethylene (TCE) was selected as the model contaminant because of its environmental importance. Degradations of TCE and H2O2 by NP surface generated OH? were investigated. Depending on the ratio of iron and H2O2, TCE conversions as high as 100 % (with about 91 % dechlorination) were obtained. TCE dechlorination was also achieved in real groundwater samples with the reactive membranes.  相似文献   

20.
The clinical use of the anticancer drug doxorubicin (DOX) is limited by strong side effects and phenomena of cell resistance. Drug targeting by binding DOX to nanoparticles could overcome these limitations. We recently described a method to associate DOX to superparamagnetic iron oxide nanoparticles (SPION) in view of magnetic drug targeting (Munnier et al. in Int J Pharm 363:170–176, 2008). DOX is bound to the nanoparticle surface through a pre-formed DOX–Fe2+ complex. The DOX-loaded SPION present interesting properties in terms of drug loading and biological activity in vitro. The purpose of this study is to explore the possible mechanisms of the in vitro cytotoxicity of DOX-loaded SPION. The uptake of SPION was followed qualitatively by conventional optical microscopy after Prussian blue staining and quantitatively by iron determination by atomic absorption spectroscopy. The subcellular distribution of intrinsically fluorescent DOX was followed by confocal spectral imaging (CSI) and the subsequent cytotoxicity by the MTT method. We reveal modifications of DOX intracellular interactions for SPION-delivered drug and increased cytotoxicity. These results are discussed in terms of internalization route of the drug and of a potential role of iron oxide nanoparticles in the observed cytotoxicity.  相似文献   

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