| Abstract [eng] |
The overall aim of the study is to identify the general rules for intracellular uptake and localisation of non-targeted nanoparticles by employing colloid quantum dots (QDs) as a model of biocompatible nanoparticle-based drug carriers. The investigation of intracellular uptake of non-targeted negatively charged QDs with fluorescence spectroscopy method revealed three time-related accumulation stages, which are characteristic for all investigated cell lines, but the stages were of different timing for each of the investigated cell line. The confocal fluorescence microscopy imaging showed four intracellular accumulation phases of QDs based on type and localisation of formed vesicles. The fluorescence lifetime imaging microscopy revealed the inner heterogeneity of intracellular vesicles: the endosomes at particular stage of maturity can be identified by different photoluminescence lifetimes of accumulated QDs. QDs do not penetrate plasma membranes through passive diffusion, but enter a cell through endocytosis. Negatively charged QDs without protein corona enter the cells through the single, caveolin-dependent endocytic pathway. Examination of the possibility to combine QDs, as model diagnostic probes, with anticancer agent in vitro revealed, that despite QDs alone had no cytotoxic effects on cells viability, they increased drug resistance. Therefore, this effect needs profound further research before the application of quantum dots in combined diagnosis and therapy in vivo. |
