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Selection of Aptamers for Amyloid β-Protein, the Causative Agent of Alzheimer's Disease
Published on: May 13, 2010
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Rhenium and technetium complexes that bind to amyloid-β plaques
David J Hayne1, Andrea J North, Michelle Fodero-Tavoletti
1School of Chemistry, University of Melbourne, Melbourne, 3010, Australia. pauld@unimelb.edu.au.
Dalton Transactions (Cambridge, England : 2003)
|December 18, 2014
Summary
New technetium complexes show potential for diagnosing Alzheimer's disease by targeting amyloid plaques. However, initial studies indicate limited brain uptake, requiring further research for effective diagnostic imaging.
Area of Science:
- Radiochemistry
- Neuroscience
- Medical Imaging
Background:
- Alzheimer's disease (AD) is characterized by amyloid plaques, primarily aggregated amyloid-beta peptide.
- Diagnostic imaging of amyloid plaques is crucial for assessing disease burden.
- Technetium-99m complexes offer potential for Single Photon Emission Computed Tomography (SPECT) imaging.
Purpose of the Study:
- To develop and evaluate technetium-99m complexes for binding to amyloid-beta plaques.
- To assess the stability and blood-brain barrier penetration potential of these complexes.
- To investigate the in vivo biodistribution of technetium complexes in an Alzheimer's disease mouse model.
Main Methods:
- Synthesis of rhenium and technetium carbonyl complexes with tridentate ligands containing stilbene functional groups.
- Evaluation of complex binding to amyloid-beta in human brain tissue.
- Assessment of complex stability in human serum.
- Lipophilicity measurements (log D7.4).
- Biodistribution studies in APP/PS1 AD mouse model.
Main Results:
- Rhenium complexes demonstrated binding to amyloid-beta in Alzheimer's disease brain tissue.
- Analogous technetium-99m complexes were synthesized and found to be stable in human serum.
- Technetium complexes exhibited suitable lipophilicity for potential blood-brain barrier penetration.
- Preliminary biodistribution studies showed low brain uptake (0.24% ID g(-1) at 2 min) in the AD mouse model.
Conclusions:
- Technetium-99m carbonyl complexes with stilbene ligands show promise for targeting amyloid plaques in Alzheimer's disease.
- Complex stability and lipophilicity are favorable for diagnostic applications.
- Further optimization is needed to enhance brain uptake for effective SPECT imaging of amyloid burden.
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