Guided by Enzymes: Targeted Photodynamic Therapy as a Strategy for Precision Medicine

Area of Science:

• Oncology
• Photomedicine
• Biochemistry

Background:

• Photodynamic therapy (PDT) is a non-invasive cancer treatment with controlled cytotoxicity.
• Current photosensitizers (PSs) often lack tumor specificity, limiting PDT efficacy.
• Targeted PDT (tPDT) aims to improve specificity by directing PSs to tumor tissues.

Purpose of the Study:

• To review enzyme-targeted tPDT strategies using metal-based PSs conjugated to enzyme inhibitors.
• To explore the dual-action mechanism of tumor destruction and pathway inhibition.
• To highlight the versatility of this approach across different enzyme targets.

Main Methods:

• Review of literature on enzyme-targeted tPDT.
• Focus on metal-based PSs conjugated with small-molecule enzyme inhibitors.
• Case studies involving carbonic anhydrase (CA), cathepsin B, cyclooxygenase (COX), epidermal growth factor receptor (EGFR), and heat shock protein 90 (Hsp90) inhibitors.

Main Results:

• Metal-based PSs conjugated to enzyme inhibitors demonstrate dual-action capabilities.
• Successful targeting and inhibition of specific enzymes involved in tumor growth.
• Demonstrated versatility of enzyme-directed tPDT for various cancer-related proteins.

Conclusions:

• Enzyme-directed tPDT offers enhanced tumor specificity and therapeutic efficacy.
• This approach minimizes off-target toxicity and collateral damage, improving patient safety.
• Enzyme-targeted tPDT integrates targeted therapy, photomedicine, and precision oncology for advanced cancer treatment.