Nanoparticles have been widely used in biological and biomedical fields. To achieve certain purpose,
nanoparticles should be functionalized with diverse molecules through genetic or chemical modification.
Therefore, we developed genetically functionalized nanoparticles for improved systems by simple
In chapter 1, we developed genetically functionalized ferritin nanoparticles for immunoassay and
imaging. Ferritins are known as self-assembled protein nanoparticles, and we fused human IgG-specific
repebody to N-terminal heavy-chain ferritin subunit to construct repebody-ferritin nanoparticles. The
repebody-ferritin nanoparticles were shown to have a three-order of magnitude higher binding affinity toward
human IgG than free repebody due to multivalency. Also, the dye-labeled repebody-ferritin nanoparticles
were applied for immunoassay such as western blot, cell imaging and flow cytometry. As a result, the
repebody-ferritin nanoparticles generated much stronger fluorescent signals than monovalent repebody.
In chapter 2, we described a targeted gene delivery system through electrostatic assembly. To deliver
genetic molecules to specific cells, we used PAMAM dendrimers and EGFR-specific repebody. A polyanionic
peptide was incorporated into EGFR-specific repebody to generate the assembly of dendrimer complex
through electrostatic interaction. The resulting dendrimer complex showed an increased efficiency with
negligible cytotoxicity in a receptor-specific manner. We confirmed the internalization of the dendrimer
complex and dissociation of plasmid DNA from the complex.
In this study, we demonstrated the utility of genetically functionalized nanoparticles for immunoassay
and gene delivery. The resulting nanoparticles can be effectively used for sensitive immunoassay and efficient targeted gene delivery.