| Abstract [eng] |
Early diagnosis and intervention of cancer tumors are essential factors in improving patient survival. Since individual imaging methods used in clinical practice are often not effective enough for early cancer detection, researchers are developing various bimodal or multimodal imaging contrast agents that enable the combination of different imaging techniques, compensating for the limitations of some methods with the advantages of the other ones. Thus, the aim of this dissertation was to evaluate the potential of different bimodal nanomaterials for cancer diagnostics. Magnetic iron oxide nanoparticles decorated with gold nanoclusters (MN-AuNCs) and rare-earth-doped upconverting nanoparticles coated with maghemite nanocrystals were studied during the experiments. These nanoparticles were biocompatible in vitro with cells, and although they did not demonstrate specificity for only cancer cells, they combined optical and magnetic resonance imaging. Moreover, under light exposure, MN-AuNCs generated reactive oxygen species capable of inducing cancer cell death, thus, the integration of bimodal imaging capabilities with therapeutic properties makes MN-AuNCs a promising theranostic nanomaterial. The third type of nanomaterial we investigated was molecular TPPS4 aggregates, which in an acidic environment self-assembled into a unique sea-urchin-like structure with a tubular central core and long branching filaments. TPPS4 aggregates exhibited fluorescence as well as second- and third-harmonic generation properties and therefore can also be classified as bimodal imaging nanomaterials. |
