Trace metal imaging with high spatial resolution: Applications in biomedicine

Abstract

New generations of analytical techniques for imaging of metals are pushing hitherto boundaries of spatial resolution and quantitative analysis in biology. Because of this, the application of these imaging techniques described herein to the study of the organization and dynamics of metal cations and metal-containing biomolecules in biological cell and tissue is becoming an important issue in biomedical research. In the current review, three common metal imaging techniques in biomedical research are introduced, including synchrotron X-ray fluorescence (SXRF) microscopy, secondary ion mass spectrometry (SIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). These are exemplified by a demonstration of the dopamine-Fe complexes, by assessment of boron distribution in a boron neutron capture therapy cell model, by mapping Cu and Zn in human brain cancer and a rat brain tumor model, and by the analysis Metallomics, 2011, 3, 28-37 29 of metal topography within neuromelanin. These studies have provided solid evidence that demonstrates that the sensitivity, spatial resolution, specificity, and quantification ability of metal imaging techniques is suitable and highly desirable for biomedical research. Moreover, these novel studies on the nanometre scale (e.g., of individual single cells or cell organelles) will lead to a better understanding of metal processes in cells and tissues.

The Physiological, Biochemical, and Molecular Roles of Zinc Transporters in Zinc Homeostasis and Metabolism

“…Zinc exists as a divalent cation (Zn 2ϩ ) and is not redox active under physiological conditions, which explains why zinc performs multifarious physiological roles in a variety of biological processes (TABLE 1). This feature of Zn 2ϩ hampered its detection, and clarification of the dynamic state of zinc was a challenge until recent improvements in zinc-imaging techniques became available, including small fluorescent sensor molecules, FRET molecules designed to sense zinc ions, X-ray fluorescence microscopy, and laser ablation inductively coupled, plasma mass spectrometry (99,174,335,338,412,425).…”

SERS in Cells: from Concepts to Practical Applications

“…We have recently shown that spatially resolved LA-ICP-MS can be employed to visualize the distribution of silver and gold nanoparticles in single cells (Figure 13.5) [85]. Beside the ease of calibration in element quantification, the multielement detection with high sensitivity and high spatial resolution makes LA-ICP-MS well-suited for single-cell analysis [79,[86][87][88].…”

High-Speed, Integrated Ablation Cell and Dual Concentric Injector Plasma Torch for Laser Ablation-Inductively Coupled Plasma Mass Spectrometry

“…Two important fields in which Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) is experiencing growing demand are those of imaging/mapping, notably of biological targets [1][2][3][4][5][6] and the analysis of discrete smallvolume samples such as single cells [7][8][9][10][11] or nanoparticulate [12][13][14] . For example this technique has been used to investigate the etiology and pathogenesis of disease states arising from imbalances in metal homeostasis.…”