Evaluation of homodimer 99mTc-HYNIC-E(SSSLTVPWY)2 peptide on HER2-over expressed breast cancer cells

The evidence resulting from a previous preclinical study of dimer LTVPWY peptide (99mTc-DLY) has proved the capability of the tracer to recognize overexpressed-HER2 on ovarian SKOV-3 tumor more specifically than its monomer counterpart (99mTc-LY). In present work, we compared HER2-directed DLY and LY peptides conjugated to 99mTc-HYNIC on SKBR-3 breast cancer cell to confirm HER2-targeting of 99mTc-DLY in breast cancerous tumors. New dimer construction of 99mTc-HYNIC-E(SSSLTVPWY)2 was labeled with a mixture of EDDA/tricine exchanging co-ligands. Afterward, it was utilized for evaluation of binding and specific binding uptakes besides, assessing the in vitro binding affinity (Kd) on SKBR-3 with high density of overexpressed-HER2. 99mTc-DLY and 99mTc-LY with high RCP (>98