A Modular Approach towards the Synthesis of Target-Specific MRI Contrast Agents

In this paper, a modular pathway towards the synthesis of new specific MRI contrast agents and their luminescent analogues is described. Using two azide-bearing probes, 3 beta-deoxycholic acid and cRGDfK(N-3), we performed a click reaction with an alkyne-bearing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) analogue, yielding a possible blood-pool contrast agent, as well as a contrast agent with a high affinity for cells expressing alpha(v)beta(3) integrin. The nuclear magnetic relaxation dispersion (NMRD) profiles and human serum albumin (HSA) titration of the contrast agent bearing deoxycholic acid show that this contrast agent interacts with HSA. T-1 measurements of Jurkat T cells in the presence of the contrast agent proved the retention of the integrin-binding property of the RGD-bearing contrast agent.