Estrogen-Functionalized Ru(II) Polypyridyl Complexes Self-Assemble into Aggregates and Exhibit Selective...

Area of Science:

• Inorganic Chemistry
• Materials Science
• Oncology

Background:

• Photodynamic therapy (PDT) offers targeted cancer treatment by generating reactive oxygen species (ROS) using photosensitizers and light.
• Current photosensitizers often lack cancer cell selectivity, leading to off-target accumulation.
• Ruthenium(II) polypyridyl complexes are promising PDT agents due to their photophysical properties and stability.

Purpose of the Study:

• To synthesize and characterize novel estrogen-functionalized ruthenium(II) complexes for targeted PDT.
• To investigate the self-assembly behavior and photophysical properties of these complexes.
• To evaluate the selective cytotoxicity of the complexes toward estrogen receptor-positive (ER+) breast cancer cells.

Main Methods:

• Synthesis of estrogen-conjugated Ru(II) complexes via click chemistry.
• Dynamic light scattering (DLS) and time-resolved luminescence studies to analyze self-assembly and photophysics.
• In vitro cytotoxicity assays comparing ER+ and ER- breast cancer cell lines upon light activation.

Main Results:

• The synthesized Ru(II) complexes self-assemble into micelle-like structures in solution.
• Two complexes demonstrated significant light-induced cytotoxicity selectively against ER+ cells (up to 9.6-fold difference).
• Complex aggregation was found to enhance cellular uptake, contributing to targeted efficacy.

Conclusions:

• Estrogen-conjugated Ru(II) complexes represent a viable strategy for targeted PDT of ER+ breast cancer.
• The observed self-assembly and aggregation behavior are crucial for enhancing cellular uptake and therapeutic effect.
• This approach minimizes damage to healthy tissues by leveraging estrogen receptor targeting.