Applications Of ZnO, Fe₃O₄ And Au Nanoparticles In Multitunotional Diagnostic And Therapeutic System

With the rocket up of nanotechnology, traditional mono-tunctional materials began to suffer from several limitations in clinical trials. Multi-functional nanomedicines, integrating multidiscipline modes from several aspects concluding therapy or diagnosis, have attracted much research interests. Different parts in corresponding platform could compensate with others, thus greatly facilitated the development of biological and medical research.In this thesis, focusing on research of quantum dots and non-invasive detection liver related disease, we have synthesized two kinds of multi-functional nanomedicine. By using in vitro and in vivo assays, we carefully tested their performance as following:Homo-dispersed ZnO QDs, obtained by the sol-gel process, were encapsulated into chitosan (CS) nanospheres through an ethanol-aided counterion complex approach. The obtained Chitosan-ZnO nanoparticles (CZNPs) are nontoxic owing to the protection of the CS nanospheres. Compared with pure ZnO QDs, the encapsulated ZnO QDs possess enhanced photoluminescence stability and longer retention time in cells. These CZNPs showed a strong blue fluorescence and could be used as cell labeling probe. The hydrophilic group and cationic charged surface of CS also provide various sites for loading anticancer drugs such as doxorubicin hydrochloride. In conclusion, the CZNPs can illuminate the cells, show the distribution of the nanospheres, and thus monitor the fate of the loaded drug, which enabled these CZNPs having a promising future in cell imaging and cancer therapyNon invasive assay for accurate diagnosis of progressive liver disease from fatty liver to hepatocellular carcinoma is of great clinical significance and still challenging. To this end, tri-modal strawberry alike Fe3O4-Au hybrid nanoparticles were synthesized via facile room temperature method. In vitro fluorescent assay give strong evidence to the photo-stability and capability to escape endosome degradation of our platform. In vivo imaging profiles of normal mice demonstrated that Fe3O4-Au nanoparticles give rise to pronounced contrast enhancement under both CT and MR guidance. In vivo performance of Fe3O4-Au NPs were further challenged with rat model bearing three different liver disease. For the fatty liver, nearly homogeneous contrast enhancement could be observed under both MR and CT guidance with no focal nodules or dysfunction. For the cirrhotic liver and hepatocellular carcinoma, pronounced enhancement under MR and CT guidance could be only seen in normal liver parenchyma with highlighted lesions post Fe3O4-Au injection. Furthermore, pathological, hematology and biochemical analysis confirmed the biocompatibility of our platform for in vivo application with absence of acute and chronic toxicity.