1
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Moore JL, Charkoftaki G. A Guide to MALDI Imaging Mass Spectrometry for Tissues. J Proteome Res 2023; 22:3401-3417. [PMID: 37877579 DOI: 10.1021/acs.jproteome.3c00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Imaging mass spectrometry is a well-established technology that can easily and succinctly communicate the spatial localization of molecules within samples. This review communicates the recent advances in the field, with a specific focus on matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) applied on tissues. The general sample preparation strategies for different analyte classes are explored, including special considerations for sample types (fresh frozen or formalin-fixed,) strategies for various analytes (lipids, metabolites, proteins, peptides, and glycans) and how multimodal imaging strategies can leverage the strengths of each approach is mentioned. This work explores appropriate experimental design approaches and standardization of processes needed for successful studies, as well as the various data analysis platforms available to analyze data and their strengths. The review concludes with applications of imaging mass spectrometry in various fields, with a focus on medical research, and some examples from plant biology and microbe metabolism are mentioned, to illustrate the breadth and depth of MALDI IMS.
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Affiliation(s)
- Jessica L Moore
- Department of Proteomics, Discovery Life Sciences, Huntsville, Alabama 35806, United States
| | - Georgia Charkoftaki
- Department of Environmental Health Sciences, Yale School of Public Health, Yale University, New Haven, Connecticut 06520, United States
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2
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Deschamps E, Calabrese V, Schmitz I, Hubert-Roux M, Castagnos D, Afonso C. Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis. Molecules 2023; 28:molecules28052061. [PMID: 36903305 PMCID: PMC10003995 DOI: 10.3390/molecules28052061] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023] Open
Abstract
Pharmaceutical analysis refers to an area of analytical chemistry that deals with active compounds either by themselves (drug substance) or when formulated with excipients (drug product). In a less simplistic way, it can be defined as a complex science involving various disciplines, e.g., drug development, pharmacokinetics, drug metabolism, tissue distribution studies, and environmental contamination analyses. As such, the pharmaceutical analysis covers drug development to its impact on health and the environment. Moreover, due to the need for safe and effective medications, the pharmaceutical industry is one of the most heavily regulated sectors of the global economy. For this reason, powerful analytical instrumentation and efficient methods are required. In the last decades, mass spectrometry has been increasingly used in pharmaceutical analysis both for research aims and routine quality controls. Among different instrumental setups, ultra-high-resolution mass spectrometry with Fourier transform instruments, i.e., Fourier transform ion cyclotron resonance (FTICR) and Orbitrap, gives access to valuable molecular information for pharmaceutical analysis. In fact, thanks to their high resolving power, mass accuracy, and dynamic range, reliable molecular formula assignments or trace analysis in complex mixtures can be obtained. This review summarizes the principles of the two main types of Fourier transform mass spectrometers, and it highlights applications, developments, and future perspectives in pharmaceutical analysis.
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Affiliation(s)
- Estelle Deschamps
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnières, CEDEX, 76821 Mont-Saint-Aignan, France
- ORIL Industrie, Servier Group, 13 r Auguste Desgenétais, 76210 Bolbec, France
| | - Valentina Calabrese
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnières, CEDEX, 76821 Mont-Saint-Aignan, France
- Université de Lyon, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, CNRS UMR 5280, 5 Rue de La Doua, F-69100 Villeurbanne, France
| | - Isabelle Schmitz
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnières, CEDEX, 76821 Mont-Saint-Aignan, France
| | - Marie Hubert-Roux
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnières, CEDEX, 76821 Mont-Saint-Aignan, France
| | - Denis Castagnos
- ORIL Industrie, Servier Group, 13 r Auguste Desgenétais, 76210 Bolbec, France
| | - Carlos Afonso
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnières, CEDEX, 76821 Mont-Saint-Aignan, France
- Correspondence:
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3
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Xu H, Hao Q, Liu H, Chen L, Wu R, Qin L, Guo H, Li J, Yang C, Hu H, Xue K, Feng J, Zhou Y, Liu B, Li G, Wang X. A concentration-descending washing strategy with methanol for the enhancement of protein imaging in biological tissues by MALDI-MS. Analyst 2023; 148:823-831. [PMID: 36637134 DOI: 10.1039/d2an01678h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a powerful approach that has been widely used for in situ detection of various endogenous compounds in tissues. However, there are still challenges with in situ analysis of proteins using MALDI-MSI due to the ion suppression effects of small molecules in tissue sections. Therefore, tissue-washing steps are crucial for protein MALDI tissue imaging to remove these interfering molecules. Here, we successfully developed a new method named the concentration-descending washing strategy (CDWS) with methanol (MeOH), i.e., washing of biological tissue with 100%, 95%, and 70% MeOH solutions, for the enhancement of endogenous in situ protein detection and imaging in tissues using MALDI-MS. The method of MeOH-based CDWS (MeOH-CDWS) led to the successful in situ detection of 272 ± 3, 185 ± 4, and 134 ± 2 protein ion signals from rat liver, rat brain, and germinating Chinese-yew seed tissue sections, respectively. By comparison, 161 ± 2, 121 ± 1, and 114 ± 2 protein ions were detected by three commonly used methods, i.e., Carnoy's wash, ethanol (EtOH)-based CAWS (i.e., concentration-ascending washing strategy, 70% EtOH followed by 90% EtOH/9% AcOH), and isopropanol (iPrOH)-based CAWS (70% iPrOH followed by 95% iPrOH), respectively, in rat liver tissue sections, indicating that 68.9 ± 3.1%, 124.8 ± 3.3%, and 138.6 ± 4.4% more protein ion signals could be detected by the use of MeOH-CDWS than the three abovementioned washing strategies. Our results show that the use of MeOH-CDWS improves the performance of MALDI-MSI for in situ protein detection such as the number and intensity of proteins. The use of MeOH-CDWS improves the fixation of proteins and thus reduces the loss of proteins, which significantly reduces protein delocalization in tissue and enhances the performance of MALDI tissue imaging of protein. Thus, the use of MeOH-CDWS improves the quality of protein images in tissue sections through MALDI-MSI and has the potential to be used as standard practice for MALDI tissue imaging of proteins.
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Affiliation(s)
- Hualei Xu
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Qichen Hao
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Haiqiang Liu
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Lulu Chen
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Ran Wu
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Liang Qin
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Hua Guo
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Jinrong Li
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Chenyu Yang
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Hao Hu
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Kun Xue
- College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Jinchao Feng
- College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Yijun Zhou
- College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
| | - Biao Liu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China, Nanjing 210042, China.
| | - Gaopeng Li
- General Surgery Department, Shanxi Bethune Hospital, Taiyuan 030032, China.
| | - Xiaodong Wang
- Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China. .,College of Life and Environmental Sciences, Centre for Imaging & Systems Biology, Minzu University of China, Beijing 100081, China
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4
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Hou JJ, Zhang ZJ, Wu WY, He QQ, Zhang TQ, Liu YW, Wang ZJ, Gao L, Long HL, Lei M, Wu WY, Guo DA. Mass spectrometry imaging: new eyes on natural products for drug research and development. Acta Pharmacol Sin 2022; 43:3096-3111. [PMID: 36229602 PMCID: PMC9712638 DOI: 10.1038/s41401-022-00990-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/25/2022] [Indexed: 11/09/2022] Open
Abstract
Natural products (NPs) and their structural analogs represent a major source of novel drug development for disease prevention and treatment. The development of new drugs from NPs includes two crucial aspects. One is the discovery of NPs from medicinal plants/microorganisms, and the other is the evaluation of the NPs in vivo at various physiological and pathological states. The heterogeneous spatial distribution of NPs in medicinal plants/microorganisms or in vivo can provide valuable information for drug development. However, few molecular imaging technologies can detect thousands of compounds simultaneously on a label-free basis. Over the last two decades, mass spectrometry imaging (MSI) methods have progressively improved and diversified, thereby allowing for the development of various applications of NPs in plants/microorganisms and in vivo NP research. Because MSI allows for the spatial mapping of the production and distribution of numerous molecules in situ without labeling, it provides a visualization tool for NP research. Therefore, we have focused this mini-review on summarizing the applications of MSI technology in discovering NPs from medicinal plants and evaluating NPs in preclinical studies from the perspective of new drug research and development (R&D). Additionally, we briefly reviewed the factors that should be carefully considered to obtain the desired MSI results. Finally, the future development of MSI in new drug R&D is proposed.
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Affiliation(s)
- Jin-Jun Hou
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zi-Jia Zhang
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wen-Yong Wu
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210029, China
| | - Qing-Qing He
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Teng-Qian Zhang
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ya-Wen Liu
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhao-Jun Wang
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Gao
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hua-Li Long
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Min Lei
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wan-Ying Wu
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - De-An Guo
- National Engineering Research Center of TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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5
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Betancourth JG, Sánchez-Rodríguez NE, Giraldo-Dávila D, Combariza MY, Chaur MN. Self-Assembled Co(II) and Zn(II) Complexes with Soluble Bis(Hydrazone)Thiopyrimidine-Based Ligands: Electrochemical and Temperature-Dependent Properties. RUSS J INORG CHEM+ 2022. [DOI: 10.1134/s0036023622600782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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6
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Wu Q. A review on quantitation-related factors and quantitation strategies in mass spectrometry imaging of small biomolecules. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:3932-3943. [PMID: 36164961 DOI: 10.1039/d2ay01257j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Accurate quantitative information of the analytes in mass spectrometry imaging (MSI) is fundamental for determining the accurate spatial distribution, which can provide additional insight into the living processes, disease progression or the pharmacokinetic-pharmacodynamic mechanisms. However, performing a quantitative analysis in MSI is still challenging. This review focuses on the quantitation-related factors and recent advances in the strategies of quantitative MSI (q-MSI) of small molecules. The main quantitation-related factors are discussed according to the new investigations in recent years, including the regionally varied extraction efficiencies and ionization efficiencies, signal-concentration regression functions, and the repeatability of surface sampling/ionization methods. Newly developed quantitation strategies in MSI based on aforementioned factors are introduced, including new techniques in standard curve calibration with normalization to an internal standard, kinetic calibration, and chemometric methods. Different strategies for validating q-MSI methods are discussed. Finally, the future perspectives to q-MSI are proposed.
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Affiliation(s)
- Qian Wu
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, 410083, P. R. China.
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7
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Gao L, Zhang Z, Wu W, Deng Y, Zhi H, Long H, Lei M, Hou J, Wu W, Guo DA. Quantitative imaging of natural products in fine brain regions using desorption electrospray ionization mass spectrometry imaging (DESI-MSI): Uncaria alkaloids as a case study. Anal Bioanal Chem 2022; 414:4999-5007. [PMID: 35639139 DOI: 10.1007/s00216-022-04130-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/28/2022] [Accepted: 05/12/2022] [Indexed: 01/21/2023]
Abstract
Uncaria species (Rubiaceae) are used as traditional Chinese medicines (TCMs) to treat central nervous system (CNS) diseases, and monoterpene indole alkaloids are the main bioactive constituents. Localization and quantification of CNS drugs in fine brain regions are important to provide insights into their pharmacodynamics, for which quantitative mass spectrometry imaging (MSI) has emerged as a powerful technique. A systematic study of the quantitative imaging of seven Uncaria alkaloids in rat brains using desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was presented. The distribution of the alkaloids in thirteen brain regions was quantified successfully using the calibration curves generated by a modified on-tissue approach. The distribution trend of different Uncaria alkaloids in the rat brain was listed as monoterpene indole alkaloids > monoterpene oxindole alkaloids, R-configuration epimers > S-configuration epimers. Particularly, Uncaria alkaloids were detected directly in the pineal gland for the first time and their enrichment phenomenon in this region had an instructive significance in future pharmacodynamic studies.
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Affiliation(s)
- Lei Gao
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zijia Zhang
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Wenyong Wu
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210029, China
| | - Yanping Deng
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Haijuan Zhi
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Huali Long
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Min Lei
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jinjun Hou
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
| | - Wanying Wu
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - De-An Guo
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
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8
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Guo S, Li K, Chen Y, Li B. Unraveling the drug distribution in brain enabled by MALDI MS imaging with laser-assisted chemical transfer. Acta Pharm Sin B 2022; 12:2120-2126. [PMID: 35847487 PMCID: PMC9279630 DOI: 10.1016/j.apsb.2021.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/24/2021] [Accepted: 11/03/2021] [Indexed: 12/15/2022] Open
Abstract
Accurate localization of central nervous system (CNS) drug distribution in the brain is quite challenging to matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI), owing to the ionization competition/suppression of highly abundant endogenous biomolecules and MALDI matrix. Herein, we developed a highly efficient sample preparation technique, laser-assisted chemical transfer (LACT), to enhance the detection sensitivity of CNS drugs in brain tissues. A focused diode laser source transilluminated the tissue slide coated with α-cyano-4-hydroxycinnamic acid, an optimal matrix to highly absorb the laser radiation at 405 nm, and a very thin-layer chemical film mainly containing drug molecule was transferred to the acceptor glass slide. Subsequently, MALDI MSI was performed on the chemical film without additional sample treatment. One major advantage of LACT is to minimize ionization competition/suppression from the tissue itself by removing abundant endogenous lipid and protein components. The superior performance of LACT led to the successful visualization of regional distribution patterns of 16 CNS drugs in the mouse brain. Furthermore, the dynamic spatial changes of risperidone and its metabolite were visualized over a 24-h period. Also, the brain-to-plasma (B/P) ratio could be obtained according to MALDI MSI results, providing an alternative means to assess brain penetration in drug discovery.
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Hahm TH, Matsui T, Tanaka M. Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging of Tissues via the Formation of Reproducible Matrix Crystals by the Fluorescence-Assisted Spraying Method: A Quantification Approach. Anal Chem 2022; 94:1990-1998. [PMID: 35040638 DOI: 10.1021/acs.analchem.1c03369] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging to quantitative analyses is restricted by the variability of MS intensity of the analytes in nonreproducible matrix crystals of tissues. To overcome this challenge, a fluorescence-assisted spraying method was developed for a constant matrix amount employing an MS-detectable fluorescent reagent, rhodamine 6G (R6G), which was sprayed with the matrix. To form a homogeneous matrix crystal on the tissue section, a matrix solution, 1,5-diaminonaphthalene (10 mg/mL), containing R6G (40 μg/mL) and O-dinitrobenzene (O-DNB, 10 mg/mL) was sprayed until the desired constant fluorescence intensity was achieved. Compared with that obtained via conventional cycle-number-fixed spraying [relative standard deviation (RSD) = 31.1%], the reproducibility of the relative MS intensity of the analyte [ferulic acid (FA), RSD = 3.1%] to R6G was significantly improved by the fluorescence-assisted matrix spraying. This result indicated that R6G could be employed as an index of the matrix amount and an MS normalizing standard. The proposed matrix spraying successfully quantified nifedipine (0.5-40 pmol/mm2 in the positive mode, R2 = 0.965) and FA (0.5-75 pmol/mm2 in the negative mode, R2 = 0.9972) in the kidney section of a rat. Employing the quantitative MALDI-MS imaging assay, FA, which accumulated in the kidney of the rat after 50 mg/kg was orally administered, was visually determined to be 3.5, 3.0, and 0.2 μmol/g tissue at 15, 30, and 60 min, respectively.
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Affiliation(s)
- Tae Hun Hahm
- Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka 819-0395, Japan
| | - Toshiro Matsui
- Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka 819-0395, Japan.,Research and Development Center for Five-Sense Devices, Kyushu University, Fukuoka 819-0395, Japan
| | - Mitsuru Tanaka
- Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka 819-0395, Japan.,Research and Development Center for Five-Sense Devices, Kyushu University, Fukuoka 819-0395, Japan
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10
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Treu A, Römpp A. Matrix ions as internal standard for high mass accuracy matrix-assisted laser desorption/ionization mass spectrometry imaging. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9110. [PMID: 33880828 DOI: 10.1002/rcm.9110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 06/12/2023]
Abstract
RATIONALE High mass accuracy is indispensable for reliable identification in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) imaging. Ubiquitous matrix ions can serve as reference masses for mass calibration if their sum formula is known. Here we report an overview of ions generated on tissue by 11 common MALDI matrices for use in internal or external mass calibration. METHODS Matrices covered in this study were applied onto coronal mouse brain sections using a pneumatic sprayer setup. MALDI imaging was performed on a Q Exactive HF orbital trapping mass spectrometer coupled to an AP-SMALDI 10 source. Measurements were conducted with high mass resolution (240 k full width at half maximum at m/z 200) and high mass accuracy with a root mean square mass error of better than 1.5 ppm achieved via internal mass calibration using matrix ions. RESULTS MALDI MS imaging was used to investigate ions generated on tissue by 11 common MALDI matrices. An example of using matrix ions for internal mass calibration in MALDI imaging of drug substances and lipids in murine lung sections is presented. Tables containing the cluster composition, sum formulae, and the measured and theoretical m/z ratios of the identified ions were compiled for each matrix. CONCLUSION Using matrix ions as reference masses for internal and external mass calibration in MALDI MS imaging is an effective and elegant way to achieve sub-ppm mass accuracy as it makes use of ubiquitous signals present in every MALDI MS spectrum without the need for an additional calibration standard.
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Affiliation(s)
- Axel Treu
- Bioanalytical Sciences and Food Analysis, University of Bayreuth, Bayreuth, Germany
| | - Andreas Römpp
- Bioanalytical Sciences and Food Analysis, University of Bayreuth, Bayreuth, Germany
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11
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Davoli E, Zucchetti M, Matteo C, Ubezio P, D'Incalci M, Morosi L. THE SPACE DIMENSION AT THE MICRO LEVEL: MASS SPECTROMETRY IMAGING OF DRUGS IN TISSUES. MASS SPECTROMETRY REVIEWS 2021; 40:201-214. [PMID: 32501572 DOI: 10.1002/mas.21633] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
Mass spectrometry imaging (MSI) has seen remarkable development in recent years. The possibility of getting quantitative or semiquantitative data, while maintaining the spatial component in the tissues has opened up unique study possibilities. Now with a spatial window of few tens of microns, we can characterize the events occurring in tissue subcompartments in physiological and pathological conditions. For example, in oncology-especially in preclinical models-we can quantitatively measure drug distribution within tumors, correlating it with pharmacological treatments intended to modify it. We can also study the local effects of the drug in the tissue, and their effects in relation to histology. This review focuses on the main results in the field of drug MSI in clinical pharmacology, looking at the literature on the distribution of drugs in human tissues, and also the first preclinical evidence of drug intratissue effects. The main instrumental techniques are discussed, looking at the different instrumentation, sample preparation protocols, and raw data management employed to obtain the sensitivity required for these studies. Finally, we review the applications that describe in situ metabolic events and pathways induced by the drug, in animal models, showing that MSI makes it possible to study effects that go beyond the simple concentration of the drug, maintaining the space dimension. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Enrico Davoli
- Laboratory of Mass Spectrometry, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Massimo Zucchetti
- Laboratory of Antitumoral Pharmacology, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Cristina Matteo
- Laboratory of Antitumoral Pharmacology, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Paolo Ubezio
- Laboratory of Antitumoral Pharmacology, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Maurizio D'Incalci
- Laboratory of Antitumoral Pharmacology, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Lavinia Morosi
- Laboratory of Antitumoral Pharmacology, Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
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12
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Abstract
Mass spectrometry imaging (MSI) is a powerful, label-free technique that provides detailed maps of hundreds of molecules in complex samples with high sensitivity and subcellular spatial resolution. Accurate quantification in MSI relies on a detailed understanding of matrix effects associated with the ionization process along with evaluation of the extraction efficiency and mass-dependent ion losses occurring in the analysis step. We present a critical summary of approaches developed for quantitative MSI of metabolites, lipids, and proteins in biological tissues and discuss their current and future applications.
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Affiliation(s)
- Daisy Unsihuay
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA; , ,
| | - Daniela Mesa Sanchez
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA; , ,
| | - Julia Laskin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA; , ,
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13
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Zhvansky ES, Ivanov DG, Sorokin AA, Bugrova AE, Nikolaev EN, Popov IA. Interactive Estimation of Heterogeneity from Mass Spectrometry Imaging. Anal Chem 2021; 93:3706-3709. [PMID: 33591173 DOI: 10.1021/acs.analchem.1c00437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we demonstrate a new approach for interactively assessing hyperspectral data spatial structures for heterogeneity using mass spectrometry imaging. This approach is based on the visualization of the cosine distance as the similarity levels between mass spectra of a chosen region and the rest of the image (sample). The applicability of the method is demonstrated on a set of mass spectrometry images of frontal mouse brain slices. Selection of the reference pixel of the mass spectrometric image and a further view of the corresponding cosine distance map helps to prepare supporting vectors for further analysis, select features, and carry out biological interpretation of different tissues in the mass spectrometry context with or without histological annotation. Visual inspection of the similarity maps reveals the spatial distribution of features in tissue samples, which can serve as the molecular histological annotation of a slide.
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Affiliation(s)
- Evgeny S Zhvansky
- Moscow Institute of Physics and Technology, Institutskij bystr. 9, 141700 Dolgoprudnyi, Moscow Region, Russia
| | - Daniil G Ivanov
- Moscow Institute of Physics and Technology, Institutskij bystr. 9, 141700 Dolgoprudnyi, Moscow Region, Russia.,Emanuel Institute for Biochemical Physics of the Russian Academy of Sciences, Kosygina st. 4, 119334 Moscow, Russia
| | - Anatoly A Sorokin
- Moscow Institute of Physics and Technology, Institutskij bystr. 9, 141700 Dolgoprudnyi, Moscow Region, Russia.,Institute of Cell Biophysics RAS, Institutskaya st., 3, 142290 Pushchino, Russia.,Institute of Systems, Molecular and Integrative Biology, Biosciences Building, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Anna E Bugrova
- Emanuel Institute for Biochemical Physics of the Russian Academy of Sciences, Kosygina st. 4, 119334 Moscow, Russia
| | - Evgeny N Nikolaev
- Skolkovo Institute of Science and Technology, Novaya Street, 100, 143025 Skolkovo, Russia
| | - Igor A Popov
- Moscow Institute of Physics and Technology, Institutskij bystr. 9, 141700 Dolgoprudnyi, Moscow Region, Russia
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14
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Zhou Q, Fülöp A, Hopf C. Recent developments of novel matrices and on-tissue chemical derivatization reagents for MALDI-MSI. Anal Bioanal Chem 2020; 413:2599-2617. [PMID: 33215311 PMCID: PMC8007514 DOI: 10.1007/s00216-020-03023-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/17/2020] [Accepted: 10/22/2020] [Indexed: 02/07/2023]
Abstract
Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a fast-growing technique for visualization of the spatial distribution of the small molecular and macromolecular biomolecules in tissue sections. Challenges in MALDI-MSI, such as poor sensitivity for some classes of molecules or limited specificity, for instance resulting from the presence of isobaric molecules or limited resolving power of the instrument, have encouraged the MSI scientific community to improve MALDI-MSI sample preparation workflows with innovations in chemistry. Recent developments of novel small organic MALDI matrices play a part in the improvement of image quality and the expansion of the application areas of MALDI-MSI. This includes rationally designed/synthesized as well as commercially available small organic molecules whose superior matrix properties in comparison with common matrices have only recently been discovered. Furthermore, on-tissue chemical derivatization (OTCD) processes get more focused attention, because of their advantages for localization of poorly ionizable metabolites and their‚ in several cases‚ more specific imaging of metabolites in tissue sections. This review will provide an overview about the latest developments of novel small organic matrices and on-tissue chemical derivatization reagents for MALDI-MSI. Graphical abstract ![]()
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Affiliation(s)
- Qiuqin Zhou
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany
| | - Annabelle Fülöp
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany
| | - Carsten Hopf
- Center for Mass Spectrometry and Optical Spectroscopy (CeMOS), Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163, Mannheim, Germany.
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15
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Stevens KG, Pukala TL. Conjugating immunoassays to mass spectrometry: Solutions to contemporary challenges in clinical diagnostics. Trends Analyt Chem 2020; 132:116064. [PMID: 33046944 PMCID: PMC7539833 DOI: 10.1016/j.trac.2020.116064] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Developments in immunoassays and mass spectrometry have independently influenced diagnostic technology. However, both techniques possess unique strengths and limitations, which define their ability to meet evolving requirements for faster, more affordable and more accurate clinical tests. In response, hybrid techniques, which combine the accessibility and ease-of-use of immunoassays with the sensitivity, high throughput and multiplexing capabilities of mass spectrometry are continually being explored. Developments in antibody conjugation methodology have expanded the role of these biomolecules to applications outside of conventional colorimetric assays and histology. Furthermore, the range of different mass spectrometry ionisation and analysis technologies has enabled its successful adaptation as a detection method for numerous clinically relevant immunological assays. Several recent examples of combined mass spectrometry-immunoassay techniques demonstrate the potential of these methods as improved diagnostic tests for several important human diseases. The present challenges are to continue technological advancements in mass spectrometry instrumentation and develop improved bioconjugation methods, which can overcome their existing limitations and demonstrate the clinical significance of these hybrid approaches.
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16
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Validation of MALDI-MS imaging data of selected membrane lipids in murine brain with and without laser postionization by quantitative nano-HPLC-MS using laser microdissection. Anal Bioanal Chem 2020; 412:6875-6886. [PMID: 32712813 PMCID: PMC7496020 DOI: 10.1007/s00216-020-02818-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/08/2020] [Accepted: 07/14/2020] [Indexed: 12/23/2022]
Abstract
MALDI mass spectrometry imaging (MALDI-MSI) is a widely used technique to map the spatial distribution of molecules in sectioned tissue. The technique is based on the systematic generation and analysis of ions from small sample volumes, each representing a single pixel of the investigated sample surface. Subsequently, mass spectrometric images for any recorded ion species can be generated by displaying the signal intensity at the coordinate of origin for each of these pixels. Although easily equalized, these recorded signal intensities, however, are not necessarily a good measure for the underlying amount of analyte and care has to be taken in the interpretation of MALDI-MSI data. Physical and chemical properties that define the analyte molecules’ adjacencies in the tissue largely influence the local extraction and ionization efficiencies, possibly leading to strong variations in signal intensity response. Here, we inspect the validity of signal intensity distributions recorded from murine cerebellum as a measure for the underlying molar distributions. Based on segmentation derived from MALDI-MSI measurements, laser microdissection (LMD) was used to cut out regions of interest with a homogenous signal intensity. The molar concentration of six exemplary selected membrane lipids from different lipid classes in these tissue regions was determined using quantitative nano-HPLC-ESI-MS. Comparison of molar concentrations and signal intensity revealed strong deviations between underlying concentration and the distribution suggested by MSI data. Determined signal intensity response factors strongly depend on tissue type and lipid species. Graphical abstract ![]()
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17
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Chen Y, Tang W, Gordon A, Li B. Development of an Integrated Tissue Pretreatment Protocol for Enhanced MALDI MS Imaging of Drug Distribution in the Brain. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1066-1073. [PMID: 32223232 DOI: 10.1021/jasms.0c00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) technique has attracted intense interest in the visualization of drug distribution in tissues. Its capability to spatially resolve individual molecules makes it a unique tool in drug development and research. However, low drug content and severe ion suppression in tissues hinder its broader application to resolve drug tissue distribution, especially small molecule drugs with a molecular weight below 500 Da. In this work, an integrated tissue pretreatment protocol was developed to enhance the detection of central nervous system drugs in the mouse brain using MALDI MSI. To evaluate the protocol, brain sections from mice dosed intraperitoneally with donepezil, tacrine, clozapine, haloperidol, and aripiprazole were used. The tissue sections were pretreated serially by washing with ammonium acetate solution, incubation with trifluoroacetic acid vapor, and n-hexane washing before MALDI MSI. Compared with the untreated sample, the signal intensities for the test drugs increased by 4.7- to 31.5-fold after pretreatment. Besides the enhancement of signal intensity, fine optimization of pretreatment time and washing solvents preserved the spatial distribution of target drug molecules. The utility of the developed protocol also provided tissue-specific distribution for five drugs which were well resolved when imaged by MALDI MS.
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Affiliation(s)
- Yanwen Chen
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Weiwei Tang
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Andrew Gordon
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Bin Li
- State Key Laboratory of Natural Medicines and School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, China
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18
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Morosi L, Matteo C, Ceruti T, Giordano S, Ponzo M, Frapolli R, Zucchetti M, Davoli E, D'Incalci M, Ubezio P. Quantitative determination of niraparib and olaparib tumor distribution by mass spectrometry imaging. Int J Biol Sci 2020; 16:1363-1375. [PMID: 32210725 PMCID: PMC7085221 DOI: 10.7150/ijbs.41395] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 01/18/2020] [Indexed: 12/15/2022] Open
Abstract
Rationale: Optimal intratumor distribution of an anticancer drug is fundamental to reach an active concentration in neoplastic cells, ensuring the therapeutic effect. Determination of drug concentration in tumor homogenates by LC-MS/MS gives important information about this issue but the spatial information gets lost. Targeted mass spectrometry imaging (MSI) has great potential to visualize drug distribution in the different areas of tumor sections, with good spatial resolution and superior specificity. MSI is rapidly evolving as a quantitative technique to measure the absolute drug concentration in each single pixel. Methods: Different inorganic nanoparticles were tested as matrices to visualize the PARP inhibitors (PARPi) niraparib and olaparib. Normalization by deuterated internal standard and a custom preprocessing pipeline were applied to achieve a reliable single pixel quantification of the two drugs in human ovarian tumors from treated mice. Results: A quantitative method to visualize niraparib and olaparib in tumor tissue of treated mice was set up and validated regarding precision, accuracy, linearity, repeatability and limit of detection. The different tumor penetration of the two drugs was visualized by MSI and confirmed by LC-MS/MS, indicating the homogeneous distribution and higher tumor exposure reached by niraparib compared to olaparib. On the other hand, niraparib distribution was heterogeneous in an ovarian tumor model overexpressing the multidrug resistance protein P-gp, a possible cause of resistance to PARPi. Conclusions: The current work highlights for the first time quantitative distribution of PAPRi in tumor tissue. The different tumor distribution of niraparib and olaparib could have important clinical implications. These data confirm the validity of MSI for spatial quantitative measurement of drug distribution providing fundamental information for pharmacokinetic studies, drug discovery and the study of resistance mechanisms.
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Affiliation(s)
- Lavinia Morosi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Cristina Matteo
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Tommaso Ceruti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Silvia Giordano
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Laboratory of Mass Spectrometry
| | - Marianna Ponzo
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Roberta Frapolli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Massimo Zucchetti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Enrico Davoli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Laboratory of Mass Spectrometry
| | - Maurizio D'Incalci
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
| | - Paolo Ubezio
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Oncology
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19
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Quantification and assessment of detection capability in imaging mass spectrometry using a revised mimetic tissue model. Bioanalysis 2019; 11:1099-1116. [PMID: 31251106 DOI: 10.4155/bio-2019-0035] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Aim: A revised method of preparing the mimetic tissue model for quantitative imaging mass spectrometry (IMS) is evaluated. Concepts of assessing detection capability are adapted from other imaging or mass spectrometry (MS)-based technologies to improve upon the reliability of IMS quantification. Materials & methods: The mimetic tissue model is prepared by serially freezing spiked-tissue homogenates into a cylindrical mold to create a plug of tissue with a stepped concentration gradient of matrix-matched standards. Weighted least squares (WLS) linear regression is applied due to the heteroscedastisity (change in variance with intensity) of most MS data. Results & conclusions: Imaging poses several caveats for quantification which are unique compared with other MS-based methods. Aspects of the design, construction, application, and evaluation of the matrix-matched standard curve for the mimetic tissue model are discussed. In addition, the criticality of the ion distribution in the design of a purposeful liquid chromatography coupled to mass spectrometry (LC-MS) validation is reviewed.
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20
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Barry JA, Ait-Belkacem R, Hardesty WM, Benakli L, Andonian C, Licea-Perez H, Stauber J, Castellino S. Multicenter Validation Study of Quantitative Imaging Mass Spectrometry. Anal Chem 2019; 91:6266-6274. [PMID: 30938516 DOI: 10.1021/acs.analchem.9b01016] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The aim of this study was to assess potential sources of variability in quantitative imaging mass spectrometry (IMS) across multiple sites, analysts, and instruments. A sample from rat liver perfused with clozapine was distributed to three sites for analysis by three analysts using a predefined protocol to standardize the sample preparation, acquisition, and data analysis parameters. In addition, two commonly used approaches to IMS quantification, the mimetic tissue model and dilution series, were used to quantify clozapine and its major metabolite norclozapine in isolated perfused rat liver. The quantification was evaluated in terms of precision and accuracy with comparison to liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The results of this study showed that, across three analysts with six replicates each, both quantitative IMS methods achieved relative standard deviations in the low teens and accuracies of around 80% compared to LC-MS/MS quantification of adjacent tissue sections. The utility of a homogeneously coated stable-isotopically labeled standard (SIL) for normalization was appraised in terms of its potential to improve precision and accuracy of quantification as well as qualitatively reduce variability in the sample tissue images. SIL normalization had a larger influence on the dilution series, where the use of the internal standard was necessary to achieve accuracy and precision comparable to the non-normalized mimetic tissue model data. Normalization to the internal standard appeared most effective when the intensity ratio of the analyte to internal standard was approximately one, and thus precludes this method as a universal normalization approach for all ions in the acquisition.
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Affiliation(s)
- Jeremy A Barry
- Bioimaging , GlaxoSmithKline , 1250 S. Collegeville Road , Collegeville , Pennsylvania 19426 , United States
| | - Rima Ait-Belkacem
- Imabiotech SAS, Parc Eurasanté , 152 rue du Docteur Yersin , 59120 Loos , France
| | - William M Hardesty
- Bioimaging , GlaxoSmithKline , 1250 S. Collegeville Road , Collegeville , Pennsylvania 19426 , United States
| | - Lydia Benakli
- Imabiotech SAS, Parc Eurasanté , 152 rue du Docteur Yersin , 59120 Loos , France
| | - Clara Andonian
- Bioanalysis , GlaxoSmithKline , 1250 S. Collegeville Road , Collegeville , Pennsylvania 19426 , United States
| | - Hermes Licea-Perez
- Bioanalysis , GlaxoSmithKline , 1250 S. Collegeville Road , Collegeville , Pennsylvania 19426 , United States
| | - Jonathan Stauber
- Imabiotech SAS, Parc Eurasanté , 152 rue du Docteur Yersin , 59120 Loos , France.,Imabiotech Corp , 44 Manning Rd , Billerica , Massachusetts 01821 , United States
| | - Stephen Castellino
- Bioimaging , GlaxoSmithKline , 1250 S. Collegeville Road , Collegeville , Pennsylvania 19426 , United States
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