In vitro imaging and human serum albumin responsive dimeric lanthanide DO3A complex

Area of Science:

• Coordination Chemistry
• Materials Science
• Biophysical Chemistry

Background:

• Lanthanide complexes are crucial for luminescence applications.
• DO3A ligands offer versatile coordination environments.
• Bridged chromophores can enhance photophysical properties.

Purpose of the Study:

• Synthesize and characterize dimeric DO3A lanthanide complexes.
• Investigate the photophysical properties and protein interactions.
• Evaluate cellular uptake and cytotoxicity for imaging.

Main Methods:

• Synthesis of dimeric DO3A lanthanide complexes.
• X-ray crystallography for structural determination.
• Photophysical measurements (luminescence spectroscopy).
• Binding studies with Human Serum Albumin (HSA).
• In vitro cellular imaging and cytotoxicity assays.

Main Results:

• Dimeric Gd and Tb complexes exhibit nine-coordinate metal ions.
• Bridged antenna in LnL(2) shows higher luminescence efficiency than LnL(1).
• LnL(2) exhibits specific binding to HSA with a high binding constant (log K = 4.84).
• EuL(2) displays superior cellular uptake and low cytotoxicity in HeLa cells compared to EuL(1).

Conclusions:

• Dimeric DO3A lanthanide complexes with bridged chromophores offer improved luminescence and protein-binding capabilities.
• The EuL(2) complex shows promise as a luminescent probe for cellular imaging due to its efficient uptake and safety profile.