Tumor Targeting with Methotrexate-Conjugated Zwitterionic Near-Infrared Fluorophore for Precise Photothermal Therapy

Area of Science:

• Oncology
• Biomedical Engineering
• Materials Science

Background:

• Targeted tumor imaging is crucial for image-guided surgery and precise cancer therapy.
• Developing effective near-infrared (NIR) fluorophores conjugated with anticancer drugs is key for photothermal cancer treatment.
• Methotrexate (MTX) is a folate antagonist with limited tumor selectivity.

Purpose of the Study:

• To develop a tumor-targetable NIR fluorophore conjugate with rapid body clearance for accurate tumor imaging and effective photothermal therapy (PTT).
• To enhance tumor accumulation and background clearance of methotrexate (MTX) through conjugation with a zwitterionic NIR fluorophore.
• To evaluate the efficacy of the MTX-ZW conjugate for NIR laser-based PTT of cancer.

Main Methods:

• Conjugation of methotrexate (MTX) with an aminated ZW800-1 analog to create the MTX-ZW conjugate.
• In vivo evaluation of tumor accumulation and background clearance of the MTX-ZW conjugate.
• Photothermal therapy (PTT) using the MTX-ZW conjugate under 808 nm laser irradiation to induce tumor cell death.

Main Results:

• The MTX-ZW conjugate demonstrated high tumor accumulation and rapid background clearance up to 4 hours post-injection.
• The conjugate effectively generated photothermal energy upon laser irradiation, inducing necrotic cell death in the targeted tumor.
• Compared to previous MTX conjugates, MTX-ZW showed improved tumor targeting and clearance properties.

Conclusions:

• The MTX-ZW conjugate is a promising candidate for targeted tumor imaging and fluorescence-guided photothermal cancer therapy.
• This study provides a novel strategy for designing drug-fluorophore conjugates for enhanced cancer phototherapy.
• The developed conjugate offers a potential therapeutic platform for precise and effective cancer treatment.