Octahedral Molybdenum Cluster-Based Nanomaterials for Potential Photodynamic Therapy

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Octahedral molybdenum clusters (Mo₆) are studied as photo/radiosensitizers for photodynamic therapy.
• Challenges include poor solubility, low stability, and unfavorable biodistribution, limiting therapeutic efficacy and increasing side effects.

Purpose of the Study:

• To develop stable, water-soluble nanomaterials for Mo₆ clusters using biocompatible polymers.
• To investigate different conjugation strategies (electrostatic, hydrophobic, covalent) for creating polymer-cluster constructs.

Main Methods:

• Synthesis of polymer-cluster constructs using N-(2-hydroxypropyl)methacrylamide (pHPMA) copolymers.
• Evaluation of conjugation strategies including electrostatic, hydrophobic, and covalent interactions.
• Assessment of luminescent properties, singlet oxygen production, and colloidal stability in various media (deionized water, PBS).

Main Results:

• All polymer-cluster constructs preserved the luminescent properties of Mo₆ clusters, indicating singlet oxygen production.
• Electrostatic and hydrophobic conjugates aggregated in phosphate buffer saline (PBS), losing structural integrity.
• Covalent conjugates demonstrated excellent colloidal stability in PBS and maintained high luminescence quantum yields.

Conclusions:

• pHPMA is a suitable nanocarrier for Mo₆ cluster-based photosensitizers.
• Covalent conjugation strategies are superior for achieving stable and effective photodynamic agents.
• These findings advance the development of nanomaterials for photodynamic therapy.