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Poster presented during WMIC (World Molecular Imaging Conference) 2011
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Organs Average ua measured
Kidney 2563
Liver 6385
Brain 16532
… …
Average ua normalized
3408
7151
26285
…
www.imabiotech.com Contact : [email protected] Imagine your next innovations
Unlike traditional imaging techniques such as autoradiography, magnetic resonance imaging or positron emission tomography, mass spectrometry imaging (MSI) permits the label-free
study of several compounds of interest simultaneously on the same tissue section. However, the difficulty of obtaining an absolute quantification of experimental data remains one of MSI’s major
disadvantages. Several methods are described in literature in order to address this issue, but none have universal applications. This quantitative MSI feasibility study investigates robustness and
reproducibility in whole-body imaging while taking pharmacokinetic problems into account. Using the example of a propranolol distribution study on whole-body, we report below the methodology
intended to respond to the main obstacles in quantification through MALDI (Matrix-Assisted Laser Desorption/Ionization) imaging. These difficulties are as follows: first, the high dependence of
the detected signal on the matrix deposition/properties and its extraction capacity; secondly, the MALDI ionization yield of specific target molecules; and lastly, the ion suppression effect on tissue.
Walkthrough
Conclusion
Example of application: Quantification of Propranolol
Figure 2 : (a) MS image of dilution range of propranolol ([M+H]+ion; m/z 260.2). (b) Calibration curve obtained for propranololdilution range (fmol/mm2), equation, linearity coefficient (R2),limit of detection (LOD) and quantification (LOQ) are reported.
Table 1 : Quantification data obtained by qMSI methodology of propranolol,BDM31343 and olanzapine compared with other techniques (liquidchromatography or quantitative whole-body autoradiography)
Introduction
COULD MASS SPECTROMETRY IMAGING BE A DRUG QUANTIFICATION TECHNIQUE? G. Hamm1, D. Bonnel1, R. Legouffe1, F. Pamelard1, J.-M. Delbos2, F. Bouzom2, C. Piveteau3, N. Willand3, B. Déprez3, J. Stauber1
1: ImaBiotech, Parc Eurasanté, Loos, France. 2: Technologie Servier, Orléans, France. 3: INSERM U761, Biostructures & Drug Discovery, University Lille Nord de France, France.
Materials and Methods
Matrix StandardWhole-body section
Concentration
Ave
rag
eua
Previously
Calculated TEC
Concentration (µg/g)
30.62
61.96
192.32
…
R²=0.9999
y=ax+b
y=ax+b
1. Evaluation of Tissue Extinction Coefficient (TEC) Applications 1 2 3
Target molecule Propranolol BDM31343 Olanzapine
Structure
Samples Mouse 20min post injection Mouse 30 min post injectionMouse kidney 2 hours post
injection
Therapeutic area Anti-hypertension Anti-tuberculosis Anti-psychotic
Preparation Sagittal cryosection (20 µm) Sagittal cryosection (10 µm)
Matrix DHB HCCA
Acquisition mode MS FAST-SRM MS
Ion images m/z 260.2 m/z 303.3→151.2 m/z 313.1
Raster size 300 µm 200 µm
Instrument: MALDI-TOF Mass Spectrometer AutoFlex Speed (Bruker Daltonik GmbH, Bremen, Germany)
equipped with a Smartbeam IIT M laser with a repetition rate of 1000Hz.
C
T
Figure 3 : (a) Scanned optical image of 20 µm thick sagittalwhole-body section of a mouse, 20 min post injection ofpropranolol. (b) Distribution of propranolol ([M+H]+ ion; m/z260) in corresponding tissues sections.
Propranolol
TissueqMSI QWBA[1] Method Comparison
% RSDConc. (µg/g tissue) % RSD Conc. (µg/g tissue)Kidney 5.6 15.9% 5.5 2.1%
Lung 17.7 13.2% 19.2 7.8%Brain 10.8 18.9% 10.3 5.0%
BDM31343
TissueqMSI LC-MS2[2] Method comparison
% RSDConc. (µg/g tissue) % RSD Conc. (µg/g tissue)Lung 39.1 12.5% 34.2 12.4%
Olanzapine
TissueqMSI LC-MS2[3] Method comparison
% RSDConc. (µg/g tissue) % RSD Conc. (µg/g tissue)Kidney 41.6 9.3% 41.1 1.1%
1. TEC Calculation 2. Calibration curve determination 3. Drug distribution study
y
Figure 1 : (a) Optical image of a control mouse whole-body section. (b) Distribution ofpropranolol at know concentration (10 pmol/µL) mixed with matrix solution is shown. (c)TEC values for each targeted organ are presented as histograms for brain, lung andkidney for propranolol.
4. Quantification
2. Calibration curve determination
3. Drug distribution study
4. Quantification
qMSI vs others quantification techniques: Advantages and disadvantages
Tissue quantitative techniques
Preparationtime
Labelling Speed DistributionSimultaneous
Metabolitedetection
Data Treatement time
Autoradiography High Yes Slow Yes No Low
Tissue extraction LC-MS²
Low No Fast No Yes High
Horizontal sectionning Low No Fast No Yes High
Spectroscopic methods High Yes Fast Yes No Low
qMSI Low No Fast Yes Yes High
qMSI Methodology:
Fast preparation
Simultaneous organ analysis
(particularly adapted to whole-
body studies)
Huge set of data and long
treatment
qMSI calculation software in
development
MALDI Imaging is a drug
quantification technique:
LOD/LOQ range (ng-µg/g tissue)
MALDI MS image
1. Kertesz et al, Analytical Chemistry 2008 80 (13), 5168-5177
2. Cornett et al, Analytical Chemistry 2008, 80 (13), 5648-5653
3. Data from INSERM
Patent FR1152334
US Patent pending