Multifunctional mixed-metal nanoscale coordination polymers for triple-modality imaging-guided photodynamic therapy

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Developing multifunctional nanomaterials for simultaneous imaging and therapy is crucial for advanced diagnostics.
• Nanoscale coordination polymers (NCPs) offer tunable properties for biomedical applications.
• Integrating multiple imaging modalities and therapeutic functions into a single agent remains a challenge.

Purpose of the Study:

• To synthesize multifunctional gadolinium-ytterbium mixed-metal NCPs using a facile one-step self-assembly method.
• To investigate the retention of inherent properties (MR, X-ray attenuation, fluorescence, singlet-oxygen generation) within the NCPs.
• To demonstrate the utility of these NCPs for in vivo triple-modality imaging and photodynamic therapy (PDT).

Main Methods:

• One-step self-assembly of gadolinium (Gd)-ytterbium (Yb) mixed-metal NCPs using Ru[4,4'-(COOH)₂bpy]₃²⁺ as a ligand.
• Tuning the Gd/Yb ratio in NCPs by adjusting precursor ratios.
• Characterization of NCP properties, including magnetic resonance (MR) response, X-ray attenuation, red fluorescence, and singlet-oxygen generation.
• In vivo evaluation for triple-modality imaging (fluorescence-MR-X-ray computed tomography) and PDT.

Main Results:

• Successfully prepared multifunctional Gd-Yb mixed-metal NCPs with tunable metal ratios and self-limiting growth.
• Preservation of Gd³⁺ (MR), Yb³⁺ (X-ray attenuation), and Ru-based ligand (fluorescence, PDT) properties within the NCPs.
• Demonstrated effective in vivo triple-modality imaging and image-guided PDT using the developed NCPs.

Conclusions:

• A robust and efficient method for preparing multifunctional Gd-Yb NCPs for integrated imaging and therapy.
• The developed NCPs offer a promising platform for sensitive, deep-penetrating, and high-resolution imaging combined with effective PDT.
• This work represents a significant advancement in the development of theranostic agents with tunable properties and multiple functionalities.