Cell imaging of dopamine receptor using agonist labeling iridium(iii) complex

Area of Science:

• Chemical Biology
• Cancer Research
• Bioimaging

Background:

• Dopamine receptor expression is linked to various cancers, including lung, breast, and colon.
• Developing specific agents for visualizing these receptors is crucial for cancer research.

Purpose of the Study:

• To develop and evaluate novel luminescent iridium(iii) complexes as intracellular dopamine receptor (D1R/D2R) imaging agents.
• To assess the selectivity, stability, and cytotoxicity of these complexes in lung cancer cells.

Main Methods:

• Synthesis and characterization of luminescent iridium(iii) complexes (11-14).
• Cell imaging studies in A549 lung cancer cells using fluorescence microscopy.
• Assays including siRNA knockdown, dopamine competitive binding, and fluorescence lifetime microscopy.

Main Results:

• Complexes 11 and 13, conjugated with a dopamine receptor agonist, demonstrated superior cell imaging properties.
• These complexes exhibited high stability and low cytotoxicity (>100 μM) in A549 cells.
• Complex 13 showed selective binding to D1R/D2R, a long luminescence lifetime, high photostability, and the ability to track receptor internalization in living cells.

Conclusions:

• Complex 13 is a novel metal-based agent for monitoring intracellular dopamine receptors in living cells.
• Its unique properties facilitate efficient and selective dopamine receptor tracking and analysis.
• This agent holds potential for advancing cancer research and diagnostics.