It is the major objective of this two-party collaborative research project to systematically unravel the detailed cytotoxic profile of quantum dot CdSe core/shell nanoparticles (NPs) with variable surface properties in contact to animal cells. We will focus on epithelial and endothelial cell species which cover all body surfaces and are most likely to encounter NPs in real life scenarios. The impact of NPs on cell viability and cell dynamics will be studied upon extracellular NP exposure but also after the NPs have been introduced into the cytoplasm by membrane electroporation. To target NPs from the cytoplasm to the nucleus or the mitochondria, NPs will be prepared with peptide motifs on their surface that are know to serve as a compartment-specific localization sequence. The cellular response to a site-specific NP exposure will be studied by means of time-resolved impedance spectroscopy performed in various modes. This non-invasive approach reads the electrical impedance of the cells when they are grown on thin-film electrodes and reports primarily on cell dynamics as universal indicator for cell viability on time scales from milliseconds to weeks. We will also study the impact of site-specific NP exposure on cell differentiation by using the murine progenitor cell line P19 as a model.
