Single-Cell Chemistry of Photoactivatable Platinum Anticancer Complexes

Area of Science:

• Inorganic Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Platinum(IV) prodrugs offer targeted cancer therapy via photoactivation.
• Pt1 and Pt2 are inert in the dark but release active platinum(II) species and radicals upon visible light irradiation.
• This photoactivation leads to photocytotoxicity in cancer cells.

Purpose of the Study:

• Investigate the in-cell behavior of Pt(IV) prodrugs Pt1 and Pt2.
• Visualize cellular morphology and platinum localization changes upon light treatment.
• Understand the mechanism of photocytotoxicity for enhanced cancer therapy.

Main Methods:

• Utilized synchrotron techniques for in-cell analysis.
• Employed X-ray absorption near-edge structure (XANES) spectroscopy.
• Observed cellular morphology and platinum distribution using advanced imaging.

Main Results:

• Photoactivation of Pt2 induced significant cellular damage and alterations, including vacuole formation.
• Cellular accumulation of platinum species increased substantially under light conditions for Pt2.
• XANES measurements indicated partial reduction of Pt2 upon irradiation, suggesting involvement of both Pt(II) and photoexcited Pt(IV) species.

Conclusions:

• Pt2 demonstrates potent photocytotoxicity, causing extensive cellular damage.
• The mechanism of phototoxicity may involve both reduced Pt(II) species and photoexcited Pt(IV) species.
• These findings advance the development of light-activated platinum-based cancer therapies.