核酸适配子共轭金纳米粒子探针成像朊蛋白细胞内在化途径

将巯基修饰的核酸适配子(aptmer)偶联到金纳米粒子(AuNPs)表面,制备出朊蛋白特异性的Apt-AuNPs纳米光学探针,并成功应用到细胞表面朊蛋白的光散射成像和电子透射显微成像分析.通过对Apt-AuNPs探针进入细胞的途径及其在细胞内命运的进一步研究表明,窖蛋白介导的内吞作用可能是其进入细胞的一个重要途径.Apt-AuNPs纳米探针制备简单、成本低廉,可能被广泛应用于生物医学成像领域.     

透明质酸-量子点的制备及应用

基于量子点(QD)独特的光学成像特性, 采用化学合成法制备了透明质酸(HA)修饰的水溶性纳米量子点(HA-QD), 并将其应用于特异性受体CD44的识别研究中. 体外细胞实验结果证实, 在透明质酸受体的介导下, 该纳米复合物可使小鼠肺腺癌细胞LA795显示特异性的荧光成像. 本研究为建立针对透明质酸受体的肿瘤活体检测及研究肿瘤的发生发展提供了重要的纳米靶向荧光探针.     

单分子定位超分辨显微成像有机荧光探针的研究进展

在生物医学领域,对纳米尺寸级别的微小生物目标进行精确定位研究具有非常重要的意义,而光学显微成像技术为此提供了强有力的工具。 光学显微成像技术受到光学衍射极限的限制,难以分辨尺寸在衍射极限(<200 nm)以下的生物结构,无法直接获取微小生物结构信息,阻碍了生物医学的进一步发展。 近年来,随着纳米分辨显微成像技术的出现,新型荧光探针的开发、成像系统与设备的不断发展及成像算法不断完善地深入结合,促进了光学衍射极限以下尺寸微观目标的研究。 基于单分子定位的超分辨荧光显微成像(SMLM)包括光激活定位成像(PALM)与随机光学重构超分辨成像(STORM),将有机荧光探针与超分辨光学显微成像技术紧密结合在一起,荧光探针的光物理性质直接决定着超分辨成像结果的好坏。 因此,设计不同性能的荧光探针可以实现超精细结构的不同超分辨成像,为研究其生物学功能提供了有力的工具。 本文着重围绕基于SMLM的原理、有机荧光探针的设计要求、用于SMLM的荧光探针种类及其生物应用等方面进行总结综述,指出了单分子定位成像上存在的不足,并对其发展方向进行了展望,希望为对超分辨成像研究感兴趣或初涉该领域的研究者提供成像理论与探针设计方面的帮助。     

单个量子点的光学性质与应用

量子点(QDs)是一种具有诸多优良光学特性的荧光纳米颗粒,已在化学分析、生物传感、分子影像等领域得到了广泛应用.单个量子点的光学性质研究有望发现一些宏观方法不能发现的实验现象,可以为改善其光学性能提供思路,有助于更好的应用于各领域.本文评述了单个量子点的检测与判定方法,单个量子点的荧光增强、漂白、眨眼(blinking)、蓝移等光学性质及其在单分子示踪、生物化学传感、超分辨定位技术等方面的应用.总结了目前量子点作为荧光探针在实际应用中遇到的问题,并提出未来量子点将朝着合成能同时满足尺寸小、量子产率高、 "non-blinking"、蓝移幅度大、无生物毒性的量子点及能同时为成像/检测提供荧光探针与散射探针的等离子体量子点等研究方向发展.     

NaYF4∶Yb3+,Er3+@NaGdF4@TaOx多模态纳米探针的合成及其在生物成像中的应用

采用溶剂热法在稀土掺杂NaYF4∶Yb3+,Er3+上转换纳米粒子上包覆一层NaGdF4,再利用反相微乳液法在NaGdF4上覆盖一层TaOx,从而合成NaYF4∶Yb3+,Er3+@NaGdF4@TaOx核壳壳结构的纳米探针。使用透射电镜(TEM)、X射线衍射(XRD)及X射线能量色散谱分析(EDS)对NaYF4∶Yb3+,Er3+@NaGdF4@TaOx纳米探针的结构和组成进行表征。并通过荧光光谱、磁滞回线以及电子计算机X射线横断扫描(CT)造影成像等方法对其性能进行了表征,证明该纳米探针具有良好的光学、磁学和CT造影特性。将NaYF4∶Yb3+,Er3+@NaG-dF4@TaOx纳米探针应用于小鼠活体成像实验,结果表明,这种纳米探针对小鼠肿瘤部位的磁共振成像(MRI)和CT信号均有较好的增强效果,表明其在多模态造影成像方面有潜在的应用前景。     

硅基纳米探针用于眼部疾病的成像检测与治疗

快速精准的诊断和高效的治疗对于减轻眼部疾病造成的危害至关重要. 在过去的几十年里, 由于具有尺寸小、 比表面积大、 表面易修饰及独特的光/电子/机械性能等优点, 纳米材料已被用于构建不同种类的高性能纳米探针. 其中, 基于其良好的生物相容性, 科学家们已经将硅纳米材料设计为可用于不同眼部疾病诊断与治疗的功能化纳米探针. 本综述主要概述了将硅基纳米探针用于检测和治疗不同眼部疾病(如角膜疾病、 视网膜疾病、 青光眼等)的近期研究进展. 首先, 重点介绍了硅基纳米探针的设计制备及在角膜新生血管、 细菌性角膜炎等角膜疾病的成像检测与治疗中的应用; 然后, 介绍了用于成像检测和治疗视网膜疾病(如色素性视网膜炎和视网膜新生血管)的硅基持续性给药系统的研究成果; 随后, 概述了多功能硅基纳米载药系统的构建及在青光眼治疗领域的应用研究进展; 最后, 简要讨论了将硅基纳米探针用于眼部疾病诊治面临的挑战并对未来的发展前景进行了展望.     

基于长余辉纳米发光探针的生物传感检测和成像

长余辉纳米粒子由于其特殊的发光现象、超长的余辉寿命、可实现免原位激发以及光谱发射区域可被调控至"生物光学透明窗口"内等特征而被广泛应用于光学传感检测和生物医学成像领域。近年来,长余辉纳米发光探针的合成和应用吸引了光谱学、声子学、光化学、材料科学领域的极大关注。本文对长余辉纳米分子探针的合成方法、颗粒表面功能化及其作为靶向探针在体内和体外进行传感检测及活体成像的应用进行深入探讨。本文主要讨论Mn~(2+)和Cr~(3+)掺杂的红色-近红外发光纳米材料,特别是镓锗酸盐,其具有强烈的近红外持续发光,超过两周的余辉寿命更适合于生物成像的应用。功能化的红色近红外长余辉纳米材料为长期实时监测体内生理学过程和疾病的诊断提供有前景的技术平台。最后本文对长余辉材料应用面临的挑战和未来的发展趋势进行了展望。     

比率成像纳米探针在内源性小分子成像中的应用

内源性信号小分子在生命活动过程中起着重要的作用,其浓度的变化和分布的异常与多种生理病理状态相关.设计可实时检测其在体内动态变化的成像体系对疾病诊断、病因探讨及细胞信号转导机制的研究至关重要.传统的检测方式多采用单一通道成像,干扰因素较多难以精确定量.近年来,比率成像纳米探针借助其独特的优势被广泛应用于生物医学领域.本文简要综述了响应于氢离子、活性氧/氮物种(ROS/RNS)和气体信号分子的比率成像纳米探针的设计原理及生物学应用.     

基于光学显微术的单粒子传感

基于光学显微术的单粒子传感技术是一种将光学显微镜等具有空间分辨能力的研究工具应用于分析传感领域的检测技术.该技术将单个纳米粒子视作一个完整的纳米传感器,分子识别和信号转换均在单个纳米粒子界面上完成,信号读取则通过不同种类的光学显微镜来实现.与宏观的纳米传感器相比,单粒子传感技术通过对单个纳米粒子的光学特征信号进行测量、计数和追踪,可以获得局域微区内分析物的定性和定量信息,从而具有高灵敏度、高通量和可用于微观复杂体系的动态检测等显著优点.首先简要回顾了单粒子光学传感技术的发展历史和国内外研究现状,随后介绍了其主要技术特点,并重点综述了该领域近五年内的重要研究成果.最后指出通过纳米探针、光学成像技术和多维数据处理等多方面的持续发展,可进一步提高单粒子光学传感器的性能,有望使其在分析科学、生命科学和材料科学等诸多领域获得更加广泛和深入的应用.     

靶向髓过氧化酶的双模态探针分子的合成与表征

5-羟色胺(5-HT)对动脉粥样硬化斑块中巨噬细胞分泌的髓过氧化酶(MPO)具有靶向功能,通过酯化反应将5-HT接枝到两亲型聚合物聚衣康酸接枝聚乙二醇接枝十二胺(PIA-g-PEG-g-DDA)上,制备了具有靶向功能的两亲型聚合物(5-HT-g-PIA-g-PEG-g-DDA).采用配体交换法,将超顺磁性氧化铁纳米粒子(SPION)包覆在该聚合物上制备具有磁性的纳米粒子(5-HT-g-PIA-g-PEG-g-DDA@SPION),通过静电力结合使其与碳点(CDs)结合,制备具有荧光成像和核磁造影成像的双模态探针的纳米粒子.采用动态光散射(DLS)及透射电子显微镜(TEM)分析了其粒径和形貌.采用荧光光谱仪与振动样品磁强计(VSM)测试证明该纳米粒子具备双模态成像功能.共聚焦成像(CLSM)的测试结果表明,该纳米试剂对动脉粥样硬化斑块中的巨噬细胞具有靶向性,MTT法的测试结果表明该探针分子具有良好的生物相容性.该双模态探针具有靶向性好、分辨率高及使用便捷的特点,是一种性能优异的双模态检测纳米试剂.     

脂质响应型探针用于动脉粥样硬化成像及治疗的研究进展

动脉粥样硬化是心血管疾病的主要威胁之一, 可能导致如急性心肌梗死在内的急性冠状动脉综合征、 卒中, 甚至猝死等一系列严重的不良后果. 脂质的异常积累是动脉粥样硬化的标志之一, 有必要观察它们在体内的数量、 定位和分布. 荧光探针具有可操作性强、 高时空分辨率和与活体生物相容性佳的优点, 有望成为了解动脉粥样硬化中的脂质功能的有利工具. 本文综合评述了基于罗丹明、 香豆素、 氟化硼二吡咯(BODIPY)、 1,8-萘酰亚胺等有机框架结构以及金属配合物的脂滴特异性光学成像探针的研究进展, 并重点介绍了其在动脉粥样硬化斑块成像、 手术导航及治疗等领域的应用. 最后, 对该研究领域进行了总结和展望, 希望可为相关研究提供有益参考.     

An Extended NIR-II Superior Imaging Window from 1500 to 1900 nm for High-Resolution In Vivo Multiplexed Imaging Based on Lanthanide Nanocrystals

High-resolution in vivo optical multiplexing in second near-infrared window (NIR-II, 1000–1700 nm) is vital to biomedical research. Presently, limited by bio-tissue scattering, only luminescent probes located at NIR-IIb (1500–1700 nm) window can provide high-resolution in vivo multiplexed imaging. However, the number of available luminescent probes in this narrow NIR-IIb region is limited, which hampers the available multiplexed channels of in vivo imaging. To overcome the above challenges, through theoretical simulation we expanded the conventional NIR-IIb window to NIR-II long-wavelength (NIR-II-L, 1500–1900 nm) window on the basis of photon-scattering and water-absorption. We developed a series of novel lanthanide luminescent nanoprobes with emission wavelengths from 1852 nm to 2842 nm. NIR-II-L nanoprobes enabled high-resolution in vivo dynamic multiplexed imaging on blood vessels and intestines, and provided multi-channels imaging on lymph tubes, tumors and intestines. The proposed NIR-II-L probes without mutual interference are powerful tools for high-contrast in vivo multiplexed detection, which holds promise for revealing physiological process in living body.     

Nanoprobes in biomedical detection

Environmental problems caused by the development of nanotechnology have threatened human health. Investigating the biomedical effects of nanomaterials can help to solve these environmental safety issues. In studies on the biomedical effects of nanomaterials, several types of novel nanoscale probes that allow reliable, sensitive, accurate and rapid biomedical detection have emerged. We summarize recent developments in three categories of these nanoprobes, including noble metal nanocluster probes, carbon-based nanostructured probes, and unnatural amino acid-based probes. Besides reviewing the utility of different nanoprobes in cell imaging and protein detection, we also discuss the molecular mechanism of nanoprobe detection. Perspectives of novel nanoprobe design based on molecular details of biomedical detection are presented.     

Design and development of quantum dots and other nanoparticles based cellular imaging probe

One goal of nanotechnology is to prepare cellular nanoprobes for various biological applications where conventional molecular probes fall short of long-term stability and simultaneous detection of multiple signals. Successful development of cellular nanoprobes requires the availability of a library of functional nanoparticles, knowledge of their interactions with cells and mechanism of cellular entry and to modulate these interactions by appropriate design of surface functionality. Although a great deal of research has been done in past 15 years, only limited success has been achieved in live cell labeling with high specificity, sub-cellular targeting and single molecule trafficking. This article focuses on the author's effort in making cellular imaging nanoprobes from different nanoparticles and discusses the most critical issues in the context of current knowledge, such as different variables that often influence labeling, non-specific binding/uptake of nanoprobes and specific live cell labeling. Finally, the important role of coating chemistry to overcome these problems has been highlighted and some successful labeling results have been summarized.     

发光ZnSalen配合物在分子荧光成像中的应用进展

荧光分子探针的设计、合成以及应用是分子荧光成像领域重要的化学问题.本文从Znsalen配合物的基本性质出发,概述了Znsalen配合物结构与功能的关系,特别是其发光性质与分子结构及分子聚集状态的相关性及应用.针对Znsalen配合物的发光性质,展示了其应用于分子荧光成像和活细胞中分子事件监测的研究进展.这些最新研究表明,Znsalen配合物探针的细胞毒性低(利于活细胞成像)、发光效率高(适用于单、双光子成像)、发光可调(通过配体的修饰和分子聚集状态的调节),有望作为一类重要的发光金属荧光探针实现在分子荧光成像中的应用.     

Silica-based nanoprobes for biomedical imaging and theranostic applications

Nanoparticle-based contrast agents are attracting a great deal of attention for various biomedical imaging and theranostic applications. Compared to conventional contrast agents, nanoparticles possess several potential advantages to improve in vivo detection and to enhance targeting efficiency. Silica-based nanoprobes can be engineered to achieve longer blood circulation times, specific clearance pathways, and multivalent binding. In this tutorial review, we summarize the latest progress on designing silica-based nanoprobes for imaging and theranostic applications. The synthesis of both solid silica and mesoporous silica nanoparticles is described, along with different approaches used for surface functionalization. Special emphasis is placed on the application of silica-based nanoprobes in optical, magnetic resonance, and multimodal imaging. The latest breakthroughs in the applications of silica nanoparticles as theranostic agents are also highlighted.     

DNA银纳米簇在功能核酸荧光生物传感器中的应用

DNA银纳米簇(DNA-AgNCs)是以DNA为模板, 通过碱基杂环上的N原子与Ag⁺结合, 用NaBH₄将Ag⁺还原得到的具有荧光性质的新兴纳米探针. 由于DNA-AgNCs具有合成方法简单、 生物相容性好和荧光发射波长可调等优点, 使其在分析检测等领域具有广泛的应用. 本文对DNA-AgNCs的合成和荧光性质两个方面进行了综述, 分类总结了以DNA-AgNCs为无标记荧光探针在功能核酸荧光生物传感器方面的应用, 对其不足与应用潜力进行展望, 以期为未来的研究与应用提供借鉴.     

DNA‐Templated Assembly of a Heterobivalent Quantum Dot Nanoprobe For Extra‐ and Intracellular Dual‐Targeting and Imaging of Live Cancer Cells

Quantum dots (QDs) hold great promise for the molecular imaging of cancer because of their superior optical properties. Although cell‐surface biomarkers can be readily imaged with QDs, non‐invasive live‐cell imaging of critical intracellular cancer markers with QDs is a great challenge because of the difficulties in the automatic delivery of QD probes to the cytosol and the ambiguity of intracellular targeting signals. Herein, we report a new type of DNA‐templated heterobivalent QD nanoprobes with the ability to target and image two spatially isolated cancer markers (nucleolin and mRNA) present on the cell surface and in the cell cytosol. Bypassing endolysosomal sequestration, this type of QD nanoprobes undergo macropinocytosis following the nucleolin targeting and then translocate to the cytosol for mRNA targeting. Fluorescence resonance energy transfer (FRET) based confocal microscopy enables unambiguous signal deconvolution of mRNA‐targeted QD nanoprobes inside cancer cells.     

Bioorthogonal SERS Nanoprobes for Mulitplex Spectroscopic Detection,Tumor Cell Targeting,and Tissue Imaging

A surface‐enhanced Raman scattering (SERS) technique shows extraordinary features for a range of biological and biomedical applications. Herein, a series of novel bioorthogonal SERS nanoprobes were constructed with Gold nanoflower (AuNF) and Raman reporters, the signals of which were located in a Raman‐silent region of biological samples. AS1411 aptamer was also co‐conjugated with AuNF through a self‐assembled monolayer coverage strategy. Multiplex SERS imaging using these nanoprobes with three different bioorthogonal small‐molecule Raman reporters is successfully achieved with high multiplexing capacity in a biologically Raman‐silent region. These Raman nanoprobes co‐conjugated with AS1411 showed high affinity for tumor cells with overexpressed nucleolin and can be used for selective tumor cell screening and tissue imaging.