Name: Ann-Christin Niehoff
Diploma / M.Sc degree: Westfälische Wilhelms-Universität Münster, Germany
(April 2013)

PhD Project: Laser ablation based elemental bioimaging and quantification

Abstract of Research Project

Methods for laser ablation based bioimaging and quantification will be developed. In this project, two different medical topics will be addressed. The first topic is based on the visualization of the photosensitizer 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP) by laser ablation (LA) coupled to an inductively-coupled plasma mass spectrometer (ICP-MS). To enable the detection of this photosensitive drug by means of ICP-MS, the photosensitizer is tagged with palladium. During this project, a method for quantitative analysis of the photosensitizer in tumor spheroids shall be developed. After quantitative elemental bioimaging, a method for molecular imaging of the photosensitizer will be developed to enable detection of the non-tagged mTHPP. The further developed method by LA-ICP-MS will be used for validation of the results.

The second topic will focus on the visualization of the bacteria staphylococcus aureus by LA-ICP-MS. Sections of heart valves from mice with endocarditis based on iron tagged S. aureus will be analyzed. Results of the bioimaging by LA-ICP-MS will be compared to results by magnetic resonance imaging (MRI) and by staining of the sections. Additionally, a method for quantitative bioimaging of the heart valve will be developed. Due to the high natural concentration of iron in tissue, the bacteria will be tagged with stable isotopic-labeled iron. Therefore, the intensity of the infection can be investigated.



Publications

A.-C. Niehoff, A. Moosmann, Judith Söbbing, A. Wiehe, D. Mulac, C. A. Wehe, O. Reifschneider, F. Blaske, S. Wagner, M. Sperling, H. von Briesen, K. Langer, U. Karst
A palladium label to monitor nanoparticle-assisted drug delivery of a photosensitizer into tumor spheroids by elemental bioimaging
Metallomics 6 (2014), 77-81.