To design efficient targeting strategies in magnetic resonance (MR) molecular imaging applications, Silvio Aime et al. from the Unviersity of Milan, Italy, explored the formation of supramolecular adducts between (strept)avidin ((S)Av) and tribiotinylated Gd-DOTA-monoamide complexes (DOTA = 1,4,7,10-tetraazacyclododecane-N,N’,N”,N”‘-tetraacetic acid).

One of these systems, endowed with high relaxivity, allowed the MRI visualization of Kaposi’s sarcoma cells and tumor endothelial cells.

• Target Visualization by MRI Using the Avidin/Biotin Amplification Route: Synthesis and Testing of a Biotin–Gd-DOTA Monoamide Trimer
  L. Tei, A. Barge, S. Geninatti Crich, R. Pagliarin, V. Negri, D. Ramella, G. Cravotto, S. Aime,
  Chem. Eur. J. 2010, 16 (27).
  DOI: 10.1002/chem.201000508