Ji-Ae Park1, Jung Young Kim1, Wonho Lee1, In Ok Ko1, Sang-Keun Woo1, Jong Guk Kim1, Joo Hyun Kang1, Sang Moo Lim2, Yongmin Chang3, Tae-Jeong Kim4, Kyeong Min Kim1
1Molecular Imaging Research Center, Korea Institute of Radiological & Medical Science, Seoul, Nowon-gu, Korea, Republic of; 2Department of Nuclear Medicine, Korea Institute of Radiological & Medical Science; 3Department of Medical & Biological Engineering, Kyungpook National University; 4Department of Applied Chemistry, Kyungpook National University
We report tumor targeting RGD conjugate Gd complex for MRI/SPECT dual imaging based on isostructural I/125I-RGD-DOTA-Gd to be a potential multimodal imaging probe. To develop a MR/SPECT dual imaging probe, YKRGD amino acids were modified with iodo-tyrosine, resulting in (iodo)YKRGD. For MR imaging agent, Gd-DOTA conjugates to (iodo)YKRGD of the type I-YKRGD-DOTA-Gd have been prepared. For SPECT imaging radioisotope, I-125, was labeled to tyrosine resulting in 125I-YKRGD-DOTA-Gd. The chemical and structural equivalence of I-YKRGD-DOTA-Gd and 125I-YKRGD-DOTA-Gd can be confirmed by HPLC. in vivo MR and SPECT imaging of tumor-bearing mice, these complexes show high specificity for receptor. These result revealed that the I/125I-RGD-DOTA-Gd would be an attractive entry into tumor-targeting dual MRI/SPECT agent.