NanoBioDetect – Nanoparticles in the tissue: detection, quantification and presentation of biological effect markers
Inhaled nanoparticles which enter the alveolar region of the lung are largely taken up and cleared from the organ by alveolar macrophages. However, a minor fraction appears to reach other cells inside the lungs or becomes distributed to remote organs where hitherto unknown effects may be induced.
To describe these processes more closely, the partners of the NanoBioDetect project aim to visualize nanoparticles with state-of-the-art imaging methods within the lungs and other target organs. To better understand effects of nanoparticles inside the body, cell types containing nanoparticles shall be identified and the mass of particles within these cells shall be quantified. Further research will focus on the detection of altered cell constituents such as protein or DNA modifications in nanoparticle-laden cells, or in regions where nanoparticles may have accumulated. Although effects of nanoparticles have been widely described for cells in vitro, most often secondary to high concentrations of nanoparticles, the meaning of these results for the complex organism still remains elusive. Knowledge of the in vivo dose of nanoparticles in experimental animals, to be collected during the project, will shed more light on these questions. Results shall furthermore be used to strengthen the predictability of in vitro assays and for setting up more appropriate in vitro assays.
The interdisciplinary work of biomedical research on cells and tissues and physico-chemical expertise shall enable the partners to solve the “dose-effect problem” for a representative selection of different nanoparticles. By means of enhanced darkfield-, Raman-, and hyperspectral microscopy particle laden sites within tissue sections will by identified and results will be controlled by electron microscopy. A special device will be developed in order to subject tissue areas pre-selected by light microscopy to further imaging tools: Ion beam microscopy (IBM) can quantitatively determine the element content via proton bombardment with high spatial resolution. Time-of-flight mass spectrometry (ToF-SIMS) is already capable to detect nanoparticles together with organic molecules but will receive further instrumental development during the project to increase efficacy and resolution. Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) will also be refined and used together with further methods (µXRF) as a quantitative approach. All these techniques shall be made compatible with biological (immuno-)detection methods. A validation of results will be achieved by comparing results from different techniques.
Eventually the best suited physical and biological detection methods will be combined in such a way that the particle content in identified cells and tissues in conjunction with biological effects becomes quantitatively describable in a reliable and cost-efficient manner.
