CXCR4 Peptide Conjugated Au-Fe 2 O 3 Nanoparticles for Tumor-targeting Magnetic Resonance Imaging

Peptide-functionalized Au-Fe2O3 nanoparticles(termed as anti-CXCR4-Au-Fe2O3 NPs) have been constructed through conjugation of dumbbell-like Au-Fe2O3 NPs with C-X-C motif chemokine receptor 4(CXCR4) binding cyclic peptide. One dumbbell-like Au-Fe2O3 NP composes an Au NP[(3.3±0.3) nm in diameter] for conjugating CXCR4 binding cyclic peptide through Au-S covalent bond and a Fe2O3 NP[(8.7±0.8) nm in diameter] for using as T2-weighted magnetic resonance imaging(MRI) contrast agent. The anti-CXCR4-Au-Fe2O3 NPs have reasonable biocompatibility and integration of T2-weighted MRI contrast and tumor-targeting functionalities. The anti-CXCR4-Au-Fe2O3 NPs exhibit strong interactions with two kinds of breast tumor cells, MCF-7 cells and MDA-MB-231 cells, and high negative contrast in MRI of MDA-MB-231 tumor bearing mouse with 62% decreasing of MRI signal, indicating that the anti-CXCR4-Au-Fe2O3 NPs can recognize tumor with high efficacy and specificity.