Organs Average ua measured

Kidney 2563

Liver 6385

Brain 16532

… …

Average ua normalized

3408

7151

26285

…

www.imabiotech.com Contact : stauber.jonathan@imabiotech.com 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