EGFR-targeted gadolinium contrast agents for enhanced molecular magnetic resonance imaging of tumors

Magnetic resonance imaging (MRI) is a widely used tool for tumor diagnosis, but current contrast agents often lack sufficient sensitivity and specificity. To address these limitations, we developed novel gadolinium-based (Gd) contrast agents conjugated with epidermal growth factor receptor (EGFR)-binding peptides (EBPs) for targeted MRI of EGFR-overexpressing tumors. The synthesized EBP-Gd-DO3A and EBP-(Gd-DO3A)₃ conjugates exhibited high binding affinity and specificity for EGFR-positive cells, as demonstrated through cell binding assays and fluorescence microscopy. Competitive binding assays confirmed EGFR-mediated specificity. In vitro MRI revealed strong contrast enhancement in EGFR-overexpressing tumor cells, while in vivo studies in xenograft models showed increased tumor uptake and prolonged contrast retention. These agents demonstrated superior specificity and sensitivity compared to traditional non-targeted Gd-DO3A, offering a promising approach for improved tumor detection, grading, and prognosis in clinical molecular imaging.