Mohammed Salman Shazeeb1,2, Christopher Howard Sotak1,3, Alexei Bogdanov, Jr.3,4
1Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA; 2Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA, USA; 3Radiology, University of Massachusetts Medical School, Worcester, MA, USA; 4Cell Biology, University of Massachusetts Medical School, Worcester, MA, USA
Specific targeted EGF receptor imaging in Gli36 tumor xenografts implanted in the rat brain was achieved using anti-EGFR monoclonal antibody conjugates (mACs) that facilitate local binding of a paramagnetic molecular substrate diTyr-DTPA(Gd) at the EGFR/EGFRvIII-overexpressing sites. Following anti-EGFR mAC administration, diTyr-DTPA(Gd) was retained for a significantly longer period of time as compared to the administration of the contrast agent without mAC or with anti-EpCAM mAC pre-treatment. Retention of diTyr-DTPA(Gd) following anti-EGFR mAC administration is consistent with enzyme-mediated coupling of the paramagnetic agent to EGFR/EGFRvIII-overexpressing cells in the tumor allowing effective MRI visualization of conjugate co-localization at the targeted site.