Research

15 pages, 4860 KiB

Open AccessArticle

Quantitative Mass Spectrometry Imaging of Bleomycin in Skin Using a Mimetic Tissue Model for Calibration

by Andreas Traberg, Fernanda E. Pinto, Anders C. N. Hansen, Merete Haedersdal, Catharina M. Lerche and Christian Janfelt

Pharmaceuticals 2022, 15(12), 1583; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15121583 - 19 Dec 2022

Cited by 6 | Viewed by 1958

Abstract

The aim of Quantitative mass spectrometry imaging (Q-MSI) is to provide distribution analysis and quantitation from one single mass-spectrometry-based experiment, and several quantitation methods have been devised for Q-MSI. Mimetic tissue models based on spiked tissue homogenates are considered one of the most [...] Read more.

The aim of Quantitative mass spectrometry imaging (Q-MSI) is to provide distribution analysis and quantitation from one single mass-spectrometry-based experiment, and several quantitation methods have been devised for Q-MSI. Mimetic tissue models based on spiked tissue homogenates are considered one of the most accurate ways to perform Q-MSI, since the analyte is present in a well-defined concentration in a sample matrix highly similar to the one of the unknown sample to be analyzed. The delivery of drugs in skin is among the most frequent types of pharmaceutical MSI studies. Here, a mimetic tissue model is extended for use on the skin, which, due to its high collagen content, is different from most other tissue as the homogenates become extremely viscous. A protocol is presented which overcomes this by the addition of water and the handling of the homogenate at an elevated temperature where the viscosity is lower. Using a mimetic tissue model, a method was developed for the quantitative imaging of bleomycin in skin. To compensate for the signal drift and the inhomogeneities in the skin, an internal standard was included in the method. The method was tested on skin from a pig which had had an electropneumatic injection of bleomycin into the skin. Quantification was made at several regions in a cross section of the skin at the injection site, and the results were compared to the results of a quantitative LC-MS on a neighboring tissue biopsy from the same animal experiment. The overall tissue concentration determined by the LC-MS was within the range of the different regions quantified by the Q-MSI. As the model provides the results of the same order of magnitude as a LC-MS, it can either be used to replace LC-MS in skin studies where MSI and LC-MS are today carried out in combination, or it can add quantitative information to skin studies which are otherwise carried out by MSI alone. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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11 pages, 3109 KiB

Open AccessCommunication

Device-Controlled Microcondensation for Spatially Confined On-Tissue Digests in MALDI Imaging of N-Glycans

by Annabelle Fülöp, Christian Marsching, Frederik Barka, Yasemin Ucal, Pauline Pfänder, Christiane A. Opitz, Günes Barka and Carsten Hopf

Pharmaceuticals 2022, 15(11), 1356; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15111356 - 03 Nov 2022

Cited by 1 | Viewed by 1730

Abstract

On-tissue enzymatic digestion is a prerequisite for MALDI mass spectrometry imaging (MSI) and spatialomic analysis of tissue proteins and their N-glycan conjugates. Despite the more widely accepted importance of N-glycans as diagnostic and prognostic biomarkers of many diseases and their potential [...] Read more.

On-tissue enzymatic digestion is a prerequisite for MALDI mass spectrometry imaging (MSI) and spatialomic analysis of tissue proteins and their N-glycan conjugates. Despite the more widely accepted importance of N-glycans as diagnostic and prognostic biomarkers of many diseases and their potential as pharmacodynamic markers, the crucial sample preparation step, namely on-tissue digestion with enzymes like PNGaseF, is currently mainly carried out by specialized laboratories using home-built incubation arrangements, e.g., petri dishes placed in an incubator. Standardized spatially confined enzyme digests, however, require precise control and possible regulation of humidity and temperature, as high humidity increases the risk of analyte dislocation and low humidity compromises enzyme function. Here, a digestion device that controls humidity by cyclic ventilation and heating of the slide holder and the chamber lid was designed to enable controlled micro-condensation on the slide and to stabilize and monitor the digestion process. The device presented here may help with standardization in MSI. Using sagittal mouse brain sections and xenografted human U87 glioblastoma cells in CD1 nu/nu mouse brain, a device-controlled workflow for MALDI MSI of N-glycans was developed. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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13 pages, 2679 KiB

Open AccessCommunication

Application of AP-MALDI Imaging Mass Microscope for the Rapid Mapping of Imipramine, Chloroquine, and Their Metabolites in the Kidney and Brain of Wild-Type Mice

by Ariful Islam, Takumi Sakamoto, Qing Zhai, Md. Muedur Rahman, Md. Al Mamun, Yutaka Takahashi, Tomoaki Kahyo and Mitsutoshi Setou

Pharmaceuticals 2022, 15(11), 1314; https://doi.org/10.3390/ph15111314 - 25 Oct 2022

Cited by 12 | Viewed by 2607

Abstract

Mass spectrometry imaging (MSI) is well-known for the non-labeling visualization of analytes, including drugs and their metabolites in biological samples. In this study, we applied three different tools of MSI, desorption electrospray ionization (DESI)-MSI, matrix-assisted laser desorption ionization (MALDI)-MSI, and a newly developed [...] Read more.

Mass spectrometry imaging (MSI) is well-known for the non-labeling visualization of analytes, including drugs and their metabolites in biological samples. In this study, we applied three different tools of MSI, desorption electrospray ionization (DESI)-MSI, matrix-assisted laser desorption ionization (MALDI)-MSI, and a newly developed atmospheric pressure (AP)-MALDI-MSI known as iMScope^TM QT for rapid mapping of imipramine, chloroquine, and their metabolites in C57BL/6 male wild-type mice. Among three MSI tools, better detection capability for targeted drugs at higher speed (up to 32 pixels/s) was observed in iMScope QT. It revealed that imipramine and its metabolites were significantly accumulated in the renal cortex of mice, but chloroquine and its metabolites were highly accumulated in the renal pelvis and renal medulla of mice. Additionally, a higher accumulation of imipramine was noted in the thalamus, hypothalamus, septum, and hindbrain of mice brains. However, chloroquine and its metabolites showed notable accumulation in the lateral ventricle, fourth ventricle, and fornix of the mice brains. These findings of our study can be helpful in understanding clinically relevant properties, efficacy, and potential side effects of these drugs. Our study also showed the potentiality of iMScope QT for rapid mapping of small drugs and their metabolites in biological samples. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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15 pages, 4870 KiB

Open AccessArticle

Evaluation of Formalin-Fixed and FFPE Tissues for Spatially Resolved Metabolomics and Drug Distribution Studies

by Andreas Dannhorn, John G. Swales, Gregory Hamm, Nicole Strittmatter, Hiromi Kudo, Gareth Maglennon, Richard J. A. Goodwin and Zoltan Takats

Pharmaceuticals 2022, 15(11), 1307; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15111307 - 23 Oct 2022

Cited by 10 | Viewed by 3946

Abstract

Fixation of samples is broadly used prior to the histological evaluation of tissue samples. Though recent reports demonstrated the ability to use fixed tissues for mass spectrometry imaging (MSI) based proteomics, glycomics and tumor classification studies, to date comprehensive evaluation of fixation-related effects [...] Read more.

Fixation of samples is broadly used prior to the histological evaluation of tissue samples. Though recent reports demonstrated the ability to use fixed tissues for mass spectrometry imaging (MSI) based proteomics, glycomics and tumor classification studies, to date comprehensive evaluation of fixation-related effects for spatially resolved metabolomics and drug disposition studies is still missing. In this study we used matrix assisted laser desorption/ionization (MALDI) and desorption electrospray ionization (DESI) MSI to investigate the effect of formalin-fixation and formalin-fixation combined with paraffin embedding on the detectable metabolome including xenobiotics. Formalin fixation was found to cause significant washout of polar molecular species, including inorganic salts, amino acids, organic acids and carnitine species, oxidation of endogenous lipids and formation of reaction products between lipids and fixative ingredients. The slow fixation kinetics under ambient conditions resulted in increased lipid hydrolysis in the tissue core, correlating with the time-dependent progression of the fixation. Paraffin embedding resulted in subsequent partial removal of structural lipids resulting in the distortion of the elucidated biodistributions. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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11 pages, 2250 KiB

Open AccessArticle

Optimization of Zebrafish Larvae Sectioning for Mass Spectrometry Imaging

by Junhai Yang, Lauren Rendino, Steven Cassar, Wayne Buck, James Sawicki, Nari Talaty and David Wagner

Pharmaceuticals 2022, 15(10), 1230; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15101230 - 07 Oct 2022

Cited by 2 | Viewed by 1968

Abstract

The utility of zebrafish is becoming more frequent due to lower costs and high similarities to humans. Zebrafish larvae are attractive subjects for drug screening and drug metabolism research. However, obtaining good quality zebrafish larvae sections for batch samples at designated planes, angles, [...] Read more.

The utility of zebrafish is becoming more frequent due to lower costs and high similarities to humans. Zebrafish larvae are attractive subjects for drug screening and drug metabolism research. However, obtaining good quality zebrafish larvae sections for batch samples at designated planes, angles, and locations for comparison purposes is a challenging task. We report here the optimization of fresh frozen zebrafish larvae sectioning for mass spectrometry imaging. We utilized the gelatin solutions that were created at two different temperatures (50 and 85 °C) as embedding media. Gelatin-50 (gelatin created under 50 °C, solid gel under room temperature) was used to make a larvae-shaped mold and gelatin-85 (gelatin created under 85 °C, liquid under room temperature) was used to embed the larvae. H&E staining of sections shows well-preserved morphology and minimal histological interference. More importantly, the position of the larvae was well controlled resulting in more consistent sectioning of the larvae. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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12 pages, 1598 KiB

Open AccessArticle

Evaluation of Quantitative Platforms for Single Target Mass Spectrometry Imaging

by Andrew P. Bowman, James Sawicki, Nari N. Talaty, Wayne R. Buck, Junhai Yang and David S. Wagner

Pharmaceuticals 2022, 15(10), 1180; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15101180 - 23 Sep 2022

Cited by 5 | Viewed by 2400

Abstract

(1) Imaging of pharmaceutical compounds in tissue is an increasingly important subsection of Mass Spectrometry Imaging (MSI). Identifying proper target engagement requires MS platforms with high sensitivity and spatial resolution. Three prominent categories of drugs are small molecule drugs, antibody-drug conjugate payloads, and [...] Read more.

(1) Imaging of pharmaceutical compounds in tissue is an increasingly important subsection of Mass Spectrometry Imaging (MSI). Identifying proper target engagement requires MS platforms with high sensitivity and spatial resolution. Three prominent categories of drugs are small molecule drugs, antibody-drug conjugate payloads, and protein degraders. (2) We tested six common MSI platforms for their limit of detection (LoD) on a representative compound for each category: a Matrix-Assisted Laser Desorption/Ionization (MALDI) Fourier Transform Ion Cyclotron, a MALDI-2 Time-of-Flight (ToF), a MALDI-2 Trapped Ion Mobility Spectrometry ToF, a Desorption Electrospray Ionization Orbitrap, and 2 Atmospheric Pressure-MALDI Triple Quadrupoles. Samples were homogenized tissue mimetic models of rat liver spiked with known concentrations of analytes. (3) We found that the AP-MALDI-QQQ platform outperformed all 4 competing platforms by a minimum of 2- to 52-fold increase in LoD for representative compounds from each category of pharmaceutical. (4) AP-MALDI-QQQ platforms are effective, cost-efficient mass spectrometers for the identification of targeted analytes of interest. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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18 pages, 4123 KiB

Open AccessArticle

Analytical Performance Evaluation of New DESI Enhancements for Targeted Drug Quantification in Tissue Sections

by Margaux Fresnais, Siwen Liang, Marius Breitkopf, Joshua Raoul Lindner, Emmanuelle Claude, Steven Pringle, Pavel A. Levkin, Konstantin Demir, Julia Benzel, Julia Sundheimer, Britta Statz, Kristian W. Pajtler, Stefan M. Pfister, Walter E. Haefeli, Jürgen Burhenne and Rémi Longuespée

Pharmaceuticals 2022, 15(6), 694; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15060694 - 01 Jun 2022

Cited by 6 | Viewed by 2892

Abstract

Desorption/ionization (DI)-mass spectrometric (MS) methods offer considerable advantages of rapidity and low-sample input for the analysis of solid biological matrices such as tissue sections. The concept of desorption electrospray ionization (DESI) offers the possibility to ionize compounds from solid surfaces at atmospheric pressure, [...] Read more.

Desorption/ionization (DI)-mass spectrometric (MS) methods offer considerable advantages of rapidity and low-sample input for the analysis of solid biological matrices such as tissue sections. The concept of desorption electrospray ionization (DESI) offers the possibility to ionize compounds from solid surfaces at atmospheric pressure, without the addition of organic compounds to initiate desorption. However, severe drawbacks from former DESI hardware stability made the development of assays for drug quantification difficult. In the present study, the potential of new prototype source setups (High Performance DESI Sprayer and Heated Transfer Line) for the development of drug quantification assays in tissue sections was evaluated. It was demonstrated that following dedicated optimization, new DESI XS enhancements present promising options regarding targeted quantitative analyses. As a model compound for these developments, ulixertinib, an inhibitor of extracellular signal-regulated kinase (ERK) 1 and 2 was used. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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12 pages, 43085 KiB

Open AccessArticle

Mapping the Lipids of Skin Sebaceous Glands and Hair Follicles by High Spatial Resolution MALDI Imaging Mass Spectrometry

by Fang Xie, Mark Reid Groseclose, Sara Tortorella, Gabriele Cruciani and Stephen Castellino

Pharmaceuticals 2022, 15(4), 411; https://0-doi-org.brum.beds.ac.uk/10.3390/ph15040411 - 28 Mar 2022

Cited by 3 | Viewed by 3251

Abstract

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a technology that utilizes the high sensitivity and specificity of mass spectrometry, combined with a high spatial resolution to characterize the molecular species present in skin tissue. In this article, we use MALDI IMS [...] Read more.

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a technology that utilizes the high sensitivity and specificity of mass spectrometry, combined with a high spatial resolution to characterize the molecular species present in skin tissue. In this article, we use MALDI IMS to map specific lipids characteristic of two important skin appendages in minipig skin: the sebaceous glands and hair follicles. A set of specific lipid markers linked to the synthesis of sebum, stages of sebum production, and the secretion of sebum for two different sebaceous gland subzones, the peripheral and central necrotic, were identified. Furthermore, biochemical pathway analysis of the identified markers provides potential drug-targeting strategies to reduce sebum overproduction in pathological conditions. In addition, specific lipid markers characteristic of the different layers in the hair follicle bulge area, including the outer root sheath, the inner root sheath, and the medulla that are associated with the growth cycles of the hair, were determined. This research highlights the ability of MALDI IMS to link a molecular distribution not only to the morphological features in skin tissue but to the physiological state as well. Thus, this platform can provide a basis for the investigation of biochemical pathways as well as the mechanisms of disease and pharmacology in the skin, which will ultimately be critical for drug discovery and the development of dermatology-related illnesses. Full article

(This article belongs to the Special Issue Mass Spectrometry Imaging in Pharmaceutical Research)

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