Abstract #1877

Gd Complexes of DO3A-(Biphenyl-2,2&[prime]-Bisamides) Conjugates as MRI Blood-Pool Contrast Agents

Ki-Hye Jung¹, Hee-Kyung Kim², Min-Kyoung Kang², Ji-Ae Park³, Eun-Young Jeon⁴, Seung-Tae Woo⁵, Joo-Hyun Kim⁵, Tae-Jeong Kim¹, Yongmin Chang²,⁶

¹Applied Chemistry, Kyungpook National University, Daegu, Korea; ²Medical & Biological Engineering, Kyungpook National University, Daegu, Korea; ³Molecular Imaging Research Center, Korea Institute of Radiological & Medical Science, Seoul, Korea; ⁴The Advanced Medical Technology Cluster for Diagnosis & Prediction, Kyounpook National University, Daegu, Korea; ⁵Bayer Healthcare, Medical care, Seoul, Korea; ⁶Diagnostic Radiology and Molecular Medicine, Kyungpook National University, Daegu, Korea

We report the synthesis of DO3A derivatives of 2,2&[prime]- diaminobiphenyl and their Gd complexes of the type [Gd(1)(H₂O)]&[middot] xH₂O (2a, b)for use as new MRI blood-pool contrast agents that provide strong and prolonged vascular enhancement. Pharmacokinetic inertness of 2 compares well with that of structurally related Dotarem, a DOTA-based MRI CA currently in use. They show interaction with HSA to give association constants (K_a) in the order of two (10²), revealing the existence of the blood-pool effect. The in-vivo MR images of mice obtained with 2 are coherent, showing strong signal enhancement in both heart, abdominal aorta, and small vessels.