Amyloid β-Binding Bifunctional Chelators with Favorable Lipophilicity for 64Cu Positron Emission Tomography Imaging in Alzheimer's Disease

Inorg Chem. 2021 Aug 16;60(16):12610-12620. doi: 10.1021/acs.inorgchem.1c02079. Epub 2021 Aug 5.

Abstract

Herein, we report a new series of bifunctional chelators (BFCs) with a high affinity for amyloid aggregates, a strong binding affinity toward Cu(II), and favorable lipophilicity for potential blood-brain barrier penetration. The alkyl carboxylate ester pendant arms offer up to 3 orders of magnitude higher binding affinity toward Cu(II) and enable the BFCs to form stable 64Cu-radiolabeled complexes. Among the five compounds tested, the 64Cu-YW-7 and 64Cu-YW-10 complexes exhibit strong and specific staining of amyloid plaques in ex vivo autoradiography studies. Importantly, these BFCs have promising partition coefficient (log Doct) values of 0.91-1.26 and show some brain uptake in biodistribution studies using CD-1 mice. Overall, these BFCs could serve as lead compounds for the development of positron emission tomography imaging agents for AD diagnosis.

MeSH terms

  • Alzheimer Disease / diagnostic imaging*
  • Alzheimer Disease / metabolism
  • Amyloid beta-Peptides / metabolism*
  • Blood-Brain Barrier / metabolism
  • Chelating Agents / chemistry*
  • Chelating Agents / metabolism*
  • Copper Radioisotopes*
  • Hydrophobic and Hydrophilic Interactions*
  • Positron-Emission Tomography*

Substances

  • Amyloid beta-Peptides
  • Chelating Agents
  • Copper Radioisotopes
  • Copper-64