Bioimaging mass spectrometry of trace elements – recent advance and applications of LA-ICP-MS: A review

Bioimaging using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers the capability to quantify trace elements and isotopes within tissue sections with a spatial resolution ranging about 10–100 μm. Distribution analysis adds to clarifying basic questions of biomedical research and enables bioaccumulation and bioavailability studies for ecological and toxicological risk assessment in humans, animals and plants. Major application fields of mass spectrometry imaging (MSI) and metallomics have been in brain and cancer research, animal model validation, drug development and plant science. Here we give an overview of latest achievements in methods and applications. Recent improvements in ablation systems, operation and cell design enabled progressively better spatial resolutions down to 1 μm. Meanwhile, a body of research has accumulated covering basic principles of the element architecture in animals and plants that could consistently be reproduced by several laboratories such as the distribution of Fe, Cu, Zn in rodent brain. Several studies investigated the distribution and delivery of metallo-drugs in animals. Hyper-accumulating plants and pollution indicator organisms have been the key topics in environmental science. Increasingly, larger series of samples are analyzed, may it be in the frame of comparisons between intervention and control groups, of time kinetics or of three-dimensional atlas approaches.     

Detection of Hg2+ ion using highly selective fluorescent chemosensor in real water sample and in-vitro cell study upon breast adenocarcinoma (MCF-7)

A novel rhodamine-based chemosensor (R) was designed and synthesised for selective recognition of Hg²⁺ ion in real water samples collected from different places. The chemosensor was prepared in green condition with high yield. The selectivity of R was examined with various metal ions, among which only Hg²⁺ was identified selectively with off–on mechanism along with enhancement of fluorescence. Metal ions recognition has been carried out using UV–vis and fluorescence studies taking µM concentration of chemosensor R in HEPES buffer. The detection limit of R was calculated and found to be 4.4 × 10^–9 M. Quantum chemical (DFT) calculation was carried out in order to acquire knowledge about the stability of R in presence of Hg²⁺ ions. Cell viability and fluorescence microscopic experiments showed R as cytocompatible and can be used as a fluorescent probe for detecting Hg²⁺ in living cells.     

稀土纳米晶用于近红外区活体成像和传感研究进展

稀土纳米晶具有丰富的激发和发射波长,良好的化学和光稳定性、大Stokes位移等特点.近年来,稀土纳米晶在生物活体成像与传感领域的应用研究取得了迅速进展.通过纳米尺度的材料设计与合成,可以对稀土纳米晶的荧光效率、波长、寿命等光学性质,以及生物相容性、靶向性、响应性等生化性质进行精细调控,使其更好地适应于活体深组织的成像与分析.先概述活体荧光成像的技术特点与要求,然后介绍稀土纳米晶的一般组成、光学性质和荧光机理,随后详细讨论对稀土纳米晶光学和生化性质进行调控的方法,着重展示这些材料的设计和修饰在生物成像与传感领域的一些最新应用.通过总结最近的研究成果,期望能够为下一步的研究提供一些参考思路,以推进基于稀土纳米晶的生物成像与传感技术的临床转化和应用.     

Introduction to Infrared and Raman-Based Biomedical Molecular Imaging and Comparison with Other Modalities

Molecular imaging has rapidly developed to answer the need of image contrast in medical diagnostic imaging to go beyond morphological information to include functional differences in imaged tissues at the cellular and molecular levels. Vibrational (infrared (IR) and Raman) imaging has rapidly emerged among the molecular imaging modalities available, due to its label-free combination of high spatial resolution with chemical specificity. This article presents the physical basis of vibrational spectroscopy and imaging, followed by illustration of their preclinical in vitro applications in body fluids and cells, ex vivo tissues and in vivo small animals and ending with a brief discussion of their clinical translation. After comparing the advantages and disadvantages of IR/Raman imaging with the other main modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography/single-photon emission-computed tomography (PET/SPECT), ultrasound (US) and photoacoustic imaging (PAI), the design of multimodal probes combining vibrational imaging with other modalities is discussed, illustrated by some preclinical proof-of-concept examples.     

Self-carried AIE nanoparticles for in vitro non-invasive long-term imaging

In this study, we report the synthesis of highly emissive AIEgen-based NPs as long-term cell trackers, which enjoy the advantages of high brightness, good stability, large Stokes shift, good biocompatibility, and high photostability. The SCA NPs were successfully applied for in vitro long-term bio-imaging of HeLa cells, indicating that the SCA NPs could be ideal fluorescent probes for non-invasive long-term cellular imaging.     

近红外二区发光稀土纳米材料的设计及生物成像应用

近年来,近红外二区(NIR-II,1000~1700 nm)荧光成像因其较高的空间分辨率、较深的组织穿透能力,在分子影像领域引起了广泛的关注。常见的NIR-II发光材料(如有机小分子、共轭聚合物、量子点等)通常具有光稳定性差、荧光量子产率低、斯托克斯位移小、荧光峰宽等问题,限制了这一新型成像技术的进一步发展与应用。稀土纳米材料由于其独特的发光特性,能够较好地克服这些不足,近年来不同结构的稀土纳米材料也逐渐被设计开发并应用于近红外二区荧光成像与检测,展示出了巨大的应用潜力。本综述首先介绍了稀土纳米材料的光学特性,然后按敏化离子的不同(Yb³⁺、Nd³⁺、Er³⁺、Tm³⁺)详细介绍了近红外二区稀土纳米材料的设计方法及相关应用,最后对稀土纳米材料在近红外二区成像领域的进一步发展进行了展望。     

钯离子荧光探针的研究进展

钯是一种重要的贵金属,在制药、燃料电池、电子电气和珠宝等行业得到广泛的应用。 然而,它的大量使用不可避免会造成其在环境中的残留,产生毒害,因此对钯的检测与识别具有重要的意义。 荧光探针具有较高的选择性、较高灵敏度、对设备依赖小、操作简单、检测限低等优点。 本文综述了近年应用于低浓度检测钯离子荧光分子探针的设计方法及作用机制。 按照荧光探针检测钯离子的响应模式,主要分为淬灭型、增强型、比率型3种方式进行评述。 尽管钯离子探针的研究在分子设计上取得了重要进展,但荧光染料与钯离子的响应时间尚且不能人为控制,尤其对于复杂体系中钯离子的检测效果尚待进一步改进。 因此,开发钯离子响应时间短、灵敏度高、专一识别性高并能应用于复杂体系的荧光探针,可能是今后主要发展方向。     

A Chromo-Fluorogenic Naphthoquinolinedione-Based Probe for Dual Detection of Cu2+ and Its Use for Various Water Samples

The presence of an abnormal amount of Cu²⁺ in the human body causes various health issues. In the current study, we synthesized a new naphthoquinolinedione-based probe (probe 1) to monitor Cu²⁺ in different water systems, such as tap water, lakes, and drain water. Two triazole units were introduced into the probe via a click reaction to increase the binding affinity to a metal ion. In day-light, probe 1 dissolved in a mixed solvent system (HEPES: EtOH = 1:4) showed a vivid color change from light greenish-yellow to pink in the presence of only Cu²⁺ among various metal ions. In addition, the green luminescence and fluorescence emission of the probe were effectively bleached out immediately after Cu²⁺ addition. The limit of detection (LOD) of the probe was 0.5 µM when a ratio-metric method was used for metal ion detection. The fluorescence titration data of the probe with Cu²⁺ showed a calculated LOD of 41.5 pM. Hence, probe 1 possesses the following dual response toward Cu²⁺ detection: color change and fluorescence quenching. Probe 1 was also useful for detecting Cu²⁺ spiked in tap/lake water as well as the cytoplasm of live HeLa cells. The current system was investigated using ultraviolet-visible and fluorescence spectroscopy as well as density functional theory calculations (DFT).     

CO2鼓泡法可控制备单层中空CaCO3微球:染料负载及细胞生物成像

在L-蛋氨酸（L-Met）的导向下,可控制备了一种单层中空CaCO₃微球。考察了L-Met的加入量、CO₂流速和反应温度等重要参数对CaCO₃形貌、尺度和晶相的影响。作为一种客体分子载体,该单层中空CaCO₃微球可负载罗丹明B（RhB）,得到一种发光复合材料（RhB@hollow-CaCO₃）。RhB@hollow-CaCO₃）对A-549肺癌细胞（A549 LCCs）和HO8910人卵巢癌细胞（HO8910 OCCs）表现出良好的生物相容性。