Multimodal imaging of 3D cell cultures using MALDI MSI and fluorescent confocal microscopy


Markéta Machálková^1,2, Jarmila Navrátilová^3,5, Barbora Pavlatovská^3, Adam Pruška^6, Jan
Michálek^4, Karel Štěpka^4, Katarzyna Anna Radaszkiewicz^3, Michal Kozubek^4, Jan Šmarda^3 and Jan
Preisler^1,2


^1 Department of Chemistry, Faculty of Science, Masaryk University

^2 Central European Institute of Technology (CEITEC), Masaryk University

^3 Department of Experimental Biology, Faculty of Science, Masaryk University

^4 Centre for Biomedical Image Analysis, Faculty of Informatics, Masaryk University

^5 Center for Biological and Cellular Engineering, International Clinical Research Center, St.
Anne's University Hospital

^6 Department of Chemistry and Applied Biosciences, Laboratory of Organic Chemistry, ETH Zurich


Multimodal imaging is emerging scientific field which combines several techniques to visualize
analytes of interest. The main goal is to obtain additional information about the sample nature
which allows accurate explanation of ongoing biological and chemical processes. Our biological
models, 3D cancer cell lines or so called spheroids, were treated by potential cancerostatic
perifosine. To visualize drug penetration within the spheroid, a matrix-assisted laser desorption
ionization mass spectrometry imaging (MALDI MSI) was used, and this was combined with fluorescent
immunohistochemistry for determination of cell viability. These two methods were executed on the
same tissue section, so the protocol for sample preparation had to be optimized. To co-localize
images from particular modalities, the fiducial based coregistration was introduced. Subsequently,
the quantification of signals was performed by so called peeling algorithm, which enabled to
segment the spheroid from the boundaries to its core. Using the precise coregistration and signal
quantification, we were able to reveal the effect of perifosine on adenocarcinoma spheroid
proliferation, apoptosis and metastasis which are important characteristics of any cancer
progression.