Mingqian Tan1,
Eun-Kee Jeong2, Zheng-Rong Lu1
1Case Western Reserve University, Cleveland,
OH, United States; 2University of Utah, Salt Lake City, UT, United
States
A
peptide targeted nanoglobular Mn(II)-DOTA conjugate was designed and
synthesized as MRI contrast agent for cancer molecular imaging. The target
specific contrast agent comprised of 2 peptides and 42 Mn(II) chelates on the
surface of the G3 nanoglobule with a defined structure. The T1 and T2
relaxivities at room temperature are 3.13 and 8.14 mM-1sec-1 per Mn(II)
chelate at 3T, respectively. The targeted nanoglobular contrast agent
specifically bound to tumor tissue and resulted in significant tumor contrast
enhancement in tumor-bearing mice as compared to a non-targeted control at a
dose as low as 0.03 mmol-Mn/kg .