New 55Co-labeled albumin-binding folate derivatives as potential PET agents for folate receptor imaging

Academic Article


  • © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Overexpression of folate receptors (FRs) on different tumor types (e.g., ovarian, lung) make FRs attractive in vivo targets for directed diagnostic/therapeutic agents. Currently, no diagnostic agent suitable for positron emission tomography (PET) has been adopted for clinical FR imaging. In this work, two55Co-labeled albumin-binding folate derivatives-[55Co]Co-cm10 and [55Co]Co-rf42-with characteristics suitable for PET imaging have been developed and evaluated. High radiochemical yields (≥95%) and in vitro stabilities (≥93%) were achieved for both compounds, and cell assays demonstrated FR-mediated uptake. Both55Co-labeled folate conjugates demonstrated high tumor uptake of 17% injected activity per gram of tissue (IA/g) at 4 h in biodistribution studies performed in KB tumor-bearing mice. Renal uptake was similar to other albumin-binding folate derivatives, and liver uptake was lower than that of previously reported [64Cu]Cu-rf42. Small animal PET/CT images confirmed the biodistribution results and showed the clear delineation of FR-expressing tumors.
  • Published In

  • Pharmaceuticals  Journal
  • Digital Object Identifier (doi)

    Author List

  • Radford LL; Fernandez S; Beacham R; Sayed RE; Farkas R; Benešová M; Müller C; Lapi SE
  • Volume

  • 12
  • Issue

  • 4