Ultrasmall c(RGDyK)-Coated Fe3O4Nanoparticles and Their Specific Targeting to Integrin αvβ3-Rich Tumor Cells

Abstract
We report a direct synthesis of ultrasmall c(RGDyK) peptide-coated Fe3O4 NPs (3O4 NPs are synthesized by thermal decomposition of iron pentacarbonyl in the presence of 4-methylcatechol (4-MC), and the peptide is coupled to the nanoparticles through 4-MC via Mannich reaction. The c(RGDyK)-MC-Fe3O4 NPs have an overall diameter of ∼8.4 nm and are stable in physiological conditions. When administrated intravenously, these c(RGDyK)-MC-Fe3O4 NPs accumulate preferentially in the integrin αvβ3-rich tumor area, which are readily tracked by MRI.