Gadolinium(III) Porphyrinoid Phototheranostics

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• Molecular phototheranostics offers non-invasive, precise, and controllable light-based medical treatments.
• Gadolinium (Gd³⁺) porphyrinoids are explored for their potential in advanced medical imaging and therapy.

Purpose of the Study:

• To develop novel Gd³⁺ porphyrinoids as dual-action agents for MRI and photodynamic therapy (PDT).
• To investigate the impact of glycosylation and β-lactonization on the photophysical and imaging properties of Gd³⁺ porphyrinoids.

Main Methods:

• Synthesis of Gd³⁺ porphyrinoids with meso-glycosylation and β-lactonization (Gd-1-4-Glu).
• Evaluation of photophysical properties, including near-infrared (NIR) absorption and reactive oxygen species (ROS) generation.
• Assessment of longitudinal relaxivity (r₁) and in vivo MRI and PDT efficacy in HeLa tumor-bearing mice.

Main Results:

• β-lactonization red-shifted absorption to the NIR region and enhanced ROS generation (type I and II pathways).
• Modified Gd³⁺ porphyrinoids achieved a high relaxivity of up to 4.3±0.2 mM^-1s^-1.
• In vivo studies demonstrated real-time T₁-weighted MRI and effective PDT in tumor-bearing mice.

Conclusions:

• Gd³⁺ porphyrinoids with glycosylation and β-lactonization are effective phototheranostic agents.
• These agents exhibit improved biocompatibility, photophysical properties, and MRI contrast.
• The study highlights the potential of Gd³⁺ porphyrinoids for advanced applications in precision medicine and cancer therapy.