Mohammed Salman Shazeeb1,2, Christopher Howard Sotak, 1,3, Alexei Bogdanov3
1Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States; 2Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA, United States; 3Department of Radiology, University of Massachusetts Medical School, Worcester, MA, United States
Targeted EGF receptor imaging in Gli36 tumor xenografts implanted in the rat brain was achieved using monoclonal antibody (mAb) conjugates that facilitate local binding of a paramagnetic molecular substrate diTyr-DTPA(Gd) at the EGFR expression sites. Following mAb conjugate administration, diTyr-DTPA(Gd) was retained for a significantly longer period of time as compared to the administration of the contrast agent without mAb conjugate pre-treatment. The increased retention of diTyr-DTPA(Gd) following mAb conjugate administration is consistent with enzyme-mediated coupling of the paramagnetic agent to EGFR-overexpressing cells in the tumor; allowing effective MRI visualization of conjugate co-localization at the targeted site.