Nanostructured polymer assemblies stabilize photoactivatable anticancer ruthenium complexes under physiological...

Area of Science:

• Materials Science
• Chemistry
• Biomedical Engineering

Background:

• Photoactivatable ruthenium (Ru) complexes are explored for anticancer phototherapy.
• Stability of Ru complexes under physiological conditions is crucial for effective drug delivery and therapeutic outcomes.

Purpose of the Study:

• To systematically investigate the stability of two Ru-containing block copolymers and their corresponding Ru complexes.
• To evaluate the protective effect of self-assembled nanostructures on Ru moieties in various physiological media.
• To assess the suitability of Ru-containing polymer assemblies for in vivo applications.

Main Methods:

• Studied stability of Ru complexes and Ru-containing block copolymers in saline, BSA solution, and DMEM (pH 6.5 and 5.5) with glutathione (GSH).
• Monitored changes in metal-to-ligand charge transfer (MLCT) bands using UV-Vis absorption spectroscopy.
• Assessed red light activation of nanostructured polymer assemblies.

Main Results:

• Free Ru complexes exhibited significant instability in tested media within one day.
• Ru-containing polymer assemblies demonstrated remarkable stability, with minimal changes in MLCT bands.
• Self-assembled nanostructures effectively protected the Ru moieties, enhancing their stability.

Conclusions:

• Ru-containing polymer assemblies offer superior stability compared to their low-molecular weight Ru complex counterparts.
• The enhanced stability and red light activatability make these polymer assemblies promising candidates for in vivo anticancer phototherapy.