Low-Temperature Photothermal Therapy Platform Based on Pd Nanozyme-Modified Hydrogenated TiO₂

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Photothermal treatments (PTTs) face challenges with normal tissue injury and cancer cell recovery via heat shock proteins (HSPs).
• Optimizing the tumor microenvironment (TME) requires strategies to enhance PTT efficiency and minimize collateral damage.

Purpose of the Study:

• To develop a safe and effective mild photothermal treatment (mPTT) platform for cancer therapy.
• To investigate the localized catalytic chemical reactions in TME for improved PTT outcomes.

Main Methods:

• Synthesis and characterization of palladium nanozyme-modified hydrogenated TiO2 (H-TiO2@Pd).
• In vitro and in vivo evaluations of H-TiO2@Pd for peroxidase-like, glutathione oxidase-like, and photodynamic activities.
• Assessment of H-TiO2@Pd's effect on glutathione (GSH), GPX4, lipid peroxides (LPO), reactive oxygen species (ROS), and HSP70 in 4T1 cells.

Main Results:

• H-TiO2@Pd demonstrated significant peroxidase-like, glutathione oxidase-like, and photodynamic properties with good biocompatibility.
• Localized reactions induced by H-TiO2@Pd depleted GSH, downregulated GPX4, and promoted LPO and ROS accumulation.
• These reactions inhibited HSP70 function, leading to enhanced cancer cell damage under mild PTT conditions.

Conclusions:

• The developed H-TiO2@Pd platform effectively creates a unique TME for mPTT.
• This strategy enhances PTT efficiency by targeting cancer cell protective mechanisms and reducing normal tissue injury.
• Pd nanozyme-modified H-TiO2 offers a promising approach for developing safe and effective cancer treatments.