Target-Selective Fluorescence Imaging and Photocytotoxicity against H₂ O₂ High-Expressing Cancer Cells Using a Photoactivatable Theranostic Agent

Area of Science:

• Chemical Biology
• Molecular Imaging
• Theranostics

Background:

• Hydrogen peroxide (H₂O₂) is a key biomarker in various physiological and pathological processes.
• Developing selective and activatable theranostic agents is crucial for advanced diagnostics and therapeutics.

Purpose of the Study:

• To design and synthesize a novel theranostic agent capable of reacting with H₂O₂.
• To develop an agent that is photoactivatable for targeted therapeutic applications.
• To enable simultaneous fluorescence detection and photodynamic therapy.

Main Methods:

• Synthesis of a purpose-designed theranostic agent (1) incorporating arylboronic acid, pro-fluorophore, and photosensitizer moieties.
• Evaluation of H₂O₂ reactivity and resorufin release under neutral aqueous conditions.
• Assessment of cell permeability, photocytotoxicity, and selective fluorescence response in living cells.

Main Results:

• The synthesized agent selectively and effectively reacted with H₂O₂, releasing resorufin for fluorescence detection.
• The agent demonstrated cell permeability and effective photocytotoxicity upon photoirradiation.
• A selective fluorescence response to H₂O₂ was observed, even in living cultured cells.

Conclusions:

• The developed theranostic agent offers a promising platform for H₂O₂-responsive imaging and photoactivated therapy.
• The agent's ability to selectively detect H₂O₂ and induce photocytotoxicity highlights its potential in biomedical applications.
• This work contributes to the advancement of theranostic agents for precise disease monitoring and treatment.