金纳米颗粒应用于肿瘤显像和治疗的研究进展

金纳米颗粒(Gold nanoparticles,GNPs)具有许多优异的理化性质,这使其在肿瘤显像和治疗方面受到了越来越多的关注.例如:GNPs具有强的X射线衰减能力,可应用于电子计算机断层扫描(Computed tomography,CT)成像;GNPs可产生等离子体激元荧光(Plasmon en-hanced fluorescence,PEF),增强荧光成像的效果;GNPs在激发光下会产生强电磁场,可用于表面增强拉曼散射;GNPs在近红外区域有较高的局域表面等离子共振(Localized surface plasmon resonance,LSPR)效应,可以应用于光声显像(Photoacoustic Imaging,PA).GNPs具有放射增敏活性,在X射线辐射下,其表面可以产生二次辐射,从而提高放射治疗的效果;GNPs在近红外光区域表现出明显的光热效应,可将光能转化为热能,从而有效地消除肿瘤组织.此外,GNPs的表面很容易进行修饰,以用于递送药物、核酸、靶向肿瘤以及提高生物相容性.本文主要对GNPs在肿瘤显像以及治疗的研究进展进行综述.     

美国科学家揭示金纳米颗粒微观结构

纳米颗粒的广泛应用，并不意味着科学家对其微观结构已经了如指掌。美国科学家的一项最新研究，揭开了科研中经常用到的一种金纳米颗粒的神秘面纱。     

一种在硅材料表面组装金纳米颗粒的新方法

以氯金酸、L-半胱氨酸为反应试剂,利用内电流和金硫自组装效应,在硅材料表面组装了较为均一的金纳米颗粒,并利用荧光分析与硅纳米线场效应晶体管对该方法进行了相关验证。结果表明:经氢氟酸处理后的硅材料,在氯金酸和L-半胱氨酸混合溶液中反应3min可在硅表面得到较为均匀、稳定的金纳米颗粒层,其中,氯金酸浓度为0.5mmol/L,氯金酸和L-半胱氨酸浓度比为3∶1。荧光分析表明该方法组装的金颗粒表面已氨基功能化,使得金纳米颗粒修饰的硅材料在应用于生物检测时可直接醛基化修饰蛋白,简化了实验操作。同时,该方法可以在硅纳米线场效应晶体管中特异性组装金纳米颗粒,有力地支持了相关器件在疾病检测方面的应用。     

基于负载金纳米颗粒的TiO_2纳米线的SERS基底

表面增强拉曼散射(Surface enhanced Raman scattering,SERS)是一种灵敏度很高的生物检测技术。近年来有研究表明,在半导体纳米材料表面用贵金属修饰所得的结构具有很强的SERS效应。本文提出了一种基于负载金纳米颗粒的宽禁带半导体FiO_2纳米线的SERS基底。FiO_2纳米线的制备采用成本低廉、工艺简单的水热合成法,然后采用原位化学还原生长法负载Au纳米颗粒,最后引入罗丹明6G(R6G)作为探针分子,证明该SERS基底能有效增强拉曼信号,实现最低浓度为10~(12)。mol/L的R6G的检测,适合应用于包括生物分子、有机污染等在内的有机分子的痕迹检测。     

合成工艺对水相合成金纳米颗粒的影响

分别采用柠檬酸三钠和硼氢化钠为还原剂在水相中还原氯金酸制备了稳定的金纳米溶胶。通过透射电子显微镜、激光粒度分析仪、紫外-可见分光光度计对所制备的金纳米颗粒的形貌、结构、粒度分布以及光学特性进行表征,研究了还原剂用量、加热反应时间、反应温度、pH值对水相制备金纳米颗粒的影响。结果表明通过调节合成工艺,可以实现金纳米颗粒的可控生长,制备出平均粒径在5～70nm粒度分布均匀的球形金纳米颗粒。     

一种在硅材料表面组装金纳米颗粒的新方法

以氯金酸、L-半胱氨酸为反应试剂,利用内电流和金硫自组装效应,在硅材料表面组装了较为均一的金纳米颗粒,并利用荧光分析与硅纳米线场效应晶体管对该方法进行了相关验证.结果表明:经氢氟酸处理后的硅材料,在氯金酸和L_半胱氨酸混合溶液中反应3 min可在硅表面得到较为均匀、稳定的金纳米颗粒层,其中,氯金酸浓度为0.5mmol/L,氯金酸和L-半耽氨酸浓度比为3∶1.荧光分析表明该方法组装的金颗粒表面已氨基功能化,使得金纳米颗粒修饰的硅材料在应用于生物检测时可直接醛基化修饰蛋白,简化了实验操作,同时,该方法可以在硅纳米线场效应晶体管中特异性组装金纳米颗粒,有力地支持了相关器件在疾病检测方面的应用.     

具有核-壳结构的金纳米包覆磁性纳米复合颗粒的研究进展

具有核-壳结构的金纳米包覆的磁性纳米粒子,既具有磁性纳米粒子的特点又增加了金纳米的表面化学性质,近年来受到研究人员的广泛关注。简要综述了近年来国内外制备2类核-壳结构的金包铁磁性纳米复合材料的研究进展及相关应用,并对其应用前景进行了展望。     

无机纳米颗粒在癌症治疗中的研究进展

纳米材料在癌症治疗中具有重要的意义.近年来,纳米材料的研究涉及多个领域,包括药物传递、疫苗开发、抗菌、诊断、癌症治疗和成像工具等.纳米材料分为有机纳米材料和无机纳米材料,无机纳米材料因其独特的尺寸依赖性的物理化学性质和特殊的光学/电磁学特性而受到广泛关注,而这是有机纳米材料所不具备的.在癌症治疗中,选择合适的无机纳米材料与搭配方法将为治疗带来更好的效果.     

纳米金在肿瘤诊断中的应用

纳米金具有独特的理化性能,在肿瘤诊断和治疗中取得了许多重要进展.综述了纳米金的结构组成、粒径尺寸、形貌特征对其本身性能的影响,介绍了纳米金对肿瘤标志物的检测和作为造影剂对肿瘤成像的研究进展,着重评述了纳米金应用于体内外肿瘤光学成像方面的研究情况,展望了其未来的发展前景.     

Magnetic Bead/Gold Nanoparticle Double‐Labeled Primers for Electrochemical Detection of Isothermal Amplified Leishmania DNA

A novel methodology for the isothermal amplification of Leishmania DNA using labeled primers combined with the advantages of magnetic purification/preconcentration and the use of gold nanoparticle (AuNP) tags for the sensitive electrochemical detection of such amplified DNA is developed. Primers labeled with AuNPs and magnetic beads (MBs) are used for the first time for the isothermal amplification reaction, being the amplified product ready for the electrochemical detection. The electrocatalytic activity of the AuNP tags toward the hydrogen evolution reaction allows the rapid quantification of the DNA on screen‐printed carbon electrodes. Amplified products from the blood of dogs with Leishmania (positive samples) are discriminated from those of healthy dogs (blank samples). Quantitative studies demonstrate that the optimized method allows us to detect less than one parasite per microliter of blood (8 × 10^?3 parasites in the isothermal amplification reaction). This pioneering approach is much more sensitive than traditional methods based on real‐time polymerase chain reaction (PCR), and is also more rapid, cheap, and user‐friendly.     

In vivo Gold Nanoparticle Delivery of Peptide Vaccine Induces Anti‐Tumor Immune Response in Prophylactic and Therapeutic Tumor Models

Gold nanoparticles (AuNPs) are promising vehicles for cancer immunotherapy, with demonstrated efficacy in immune delivery and innate cell stimulation. Nevertheless, their potential has yet to be assessed in the in vivo application of peptide cancer vaccines. In this study, it is hypothesized that the immune distribution and adjuvant qualities of AuNPs could be leveraged to facilitate delivery of the ovalbumin (OVA) peptide antigen and the CpG adjuvant and enhance their therapeutic effect in a B16‐OVA tumor model. AuNP delivery of OVA (AuNP‐OVA) and of CpG (AuNP‐CpG) enhanced the efficacy of both agents and induced strong antigen‐specific responses. In addition, it is found that AuNP‐OVA delivery alone, without CpG, is sufficient to promote significant antigen‐specific responses, leading to subsequent anti‐tumor activity and prolonged survival in both prophylactic and therapeutic in vivo tumor models. This enhanced therapeutic efficacy is likely due to the adjuvant effect of peptide coated AuNPs, as they induce inflammatory cytokine release when cultured with bone marrow dendritic cells. Overall, AuNP‐mediated OVA peptide delivery can produce significant therapeutic benefits without the need of adjuvant, indicating that AuNPs are effective peptide vaccine carriers with the potential to permit the use of lower and safer adjuvant doses during vaccination.     

食品中丙烯酰胺检测方法的研究进展

丙烯酰胺是一种对人体有神经毒性和潜在致癌性的物质,2002年首次发现在高温油炸后的富含碳水化合物食品中存在,并引起了世界各国研究者的广泛关注。本文就丙烯酰胺的检测方法,主要包括气相色谱法与液相色谱法,进行了综述。     

纳米粒子表面功能化研究进展

纳米粒子表面改性包括物理改性和化学改性。物理改性一般采用高能表面改性法对纳米粒子进行修饰;化学改性分为硅烷偶联剂、酯化反应、表面接枝和表面活性剂等方法。     

Ag+‐Gated Surface Chemistry of Gold Nanoparticles and Colorimetric Detection of Acetylcholinesterase

Chemical regulation of enzyme‐mimic activity of nanomaterials is challenging because it requires a precise understanding of the surface chemistry and mechanism, and rationally designed applications. Herein, Ag⁺‐gated peroxidase activity is demonstrated by successfully modulating surface chemistry of cetyltrimethylammonium bromide‐capped gold nanoparticles (CTAB‐AuNPs). A surface blocking effect of long‐chain molecules on surfaces of AuNPs that inhibit peroxidase activity of AuNPs is found. Ag⁺ ions can selectively bind on the surfaces of AuNPs and competitively destroy CTAB membrane forming Ag⁺@CTAB‐AuNPs complexes to result in enhanced peroxidase activity. Ag⁺@CTAB‐AuNPs show the highest peroxidase activity compared to similar‐sized citrate‐capped and ascorbic acid‐capped AuNPs. Ag⁺@CTAB‐AuNPs can potentially develop into analyte‐responsive systems and exhibit advantages in the optical sensing field. For example, the Ag⁺@CTAB‐AuNPs system shows an enhanced sensitivity and selectivity for acetylcholinesterase activity sensing compared to other methods.     

Detection of Circulating Cancer Cells Using Electrocatalytic Gold Nanoparticles

A rapid cancer cell detection and quantification assay, based on the electrocatalytic properties of gold nanoparticles towards the hydrogen evolution reaction, is described. The selective labeling of cancer cells is performed in suspension, allowing a fast interaction between the gold nanoparticle labels and the target proteins expressed at the cell membrane. The subsequent electrochemical detection is accomplished with small volumes of sample and user‐friendly equipment through a simple electrochemical method that generates a fast electrochemical response used for the quantification of nanoparticle‐labeled cancer cells. The system establishes a selective cell‐detection assay capable of detecting 4 × 10³ cancer cells in suspension that can be extended to several other cells detection scenarios.