Epidermal Growth Factor Receptor (EGFR) Targeted MRI Using A Probe of SPIO Nanocrystal and scFv EGFR Conjugate
Cao Z, Adams G, Yuan Q, Mao H, Yang L, Peng X, Wang Y, Wang X
Emory University School of Medicine
We report our investigation of a novel MRI probe consisting of superparamagnetic iron oxide (SPIO) nanocrystals conjugated with the protein (ScFv EGFR, a single chain antibody), developed for MR imaging of EGFR over-expressed in tumors. This EGFR targeted SPIO nanocrystal-ScFv EGFR conjugate exhibits strong T1 and T2 shortening effects. Its strong specificity in binding to EGFR over expressed breast cancer cells was demonstrated by T2 MRI in cell culture. In vivo mouse MRI showed T2 contrast enhancement in the liver/spleen and delayed T1 enhancement in the kidney, indicating that this protein-SPIO complex is stable in physiological conditions.