Facets of ICP-MS and their potential in the medical sciences—Part 2: nanomedicine, immunochemistry, mass cytometry, and bioassays

Abstract

Inductively coupled–plasma mass spectrometry (ICP-MS) has transformed our knowledge on the role of trace and major elements in biology and has emerged as the most versatile technique in elemental mass spectrometry. The scope of ICP-MS has dramatically changed since its inception, and nowadays, it is a mature platform technology that is compatible with chromatographic and laser ablation (LA) systems. Over the last decades, it kept pace with various technological advances and was inspired by interdisciplinary approaches which endorsed new areas of applications. While the first part of this review was dedicated to fundamentals in ICP-MS, its hyphenated techniques and the application in biomonitoring, isotope ratio analysis, elemental speciation analysis, and elemental bioimaging, this second part will introduce relatively current directions in ICP-MS and their potential to provide novel perspectives in the medical sciences. In this context, current directions for the characterisation of novel nanomaterials which are considered for biomedical applications like drug delivery and imaging platforms will be discussed while considering different facets of ICP-MS including single event analysis and dedicated hyphenated techniques. Subsequently, immunochemistry techniques will be reviewed in their capability to expand the scope of ICP-MS enabling analysis of a large range of biomolecules alongside elements. These methods inspired mass cytometry and imaging mass cytometry and have the potential to transform diagnostics and treatment by offering new paradigms for personalised medicine. Finally, the interlacing of immunochemistry methods, single event analysis, and functional nanomaterials has opened new horizons to design novel bioassays which promise potential as assets for clinical applications and larger screening programs and will be discussed in their capabilities to detect low-level proteins and nucleic acids. Graphical abstract

Atomic spectrometry update: review of advances in elemental speciation

“…A comprehensive, two-part review examined the impact and potential of ICP-MS in the medical sciences. 17,18 In the rst part (258 references), the reviewers covered fundamentals, instrumental basics, technological advances, as well as applications of ICP-MS to biomonitoring, bioimaging and elemental speciation. The review included a substantial section devoted to "elemental speciation analysis in the medical sciences" that, naturally enough, featured many applications of HPLC-ICP-MS, but hardly any in which separation was by CZE.…”

Swimming against the current – sacrificing unit mass resolution in ICP-MS to improve figures of merit

“…6 In this immunohistochemistry-assisted LA-ICP-MS approach, the lanthanide was used as a proxy for the antibody's target and following the incubation on tissue, LA-ICP-MS was used to inquire the spatial distribution of the label. 2,4 Both high sensitivity and high spatial resolution are oen required to target specic biomarkers in highly compartmentalised structures. Provided that labels do not produce overlapping signals, the bandpass mode may improve contrasts.…”

“…4 More recent facets are its so-called single particle (SP) mode and its application in the context of cytometry. 2,5…”

Strategies to enhance figures of merit in ICP-ToF-MS

“…New applications and technology have been developed and expanded the capabilities of ICP-MS vastly since its inception. 1,2 Following its commercial introduction in 1983, 3 solid sampling, 4 bioimaging 5 and speciation analysis 6 were established by hyphenating ICP-MS with laser ablation (LA) and chromatography. 7,8 For the former, a pulsed laser is used to raster over a solid specimen and the ablated material is transported as dry aerosol for elemental analysis via ICP-MS.…”