Upconversion Nanoparticle-Induced Multimode Photodynamic Therapy Based on a Metal-Organic Framework/Titanium Dioxide...

Area of Science:

• Biomedical Engineering
• Materials Science
• Photochemistry

Background:

• Photodynamic therapy (PDT) traditionally faces limitations due to low reactive oxygen species (ROS) generation efficiency and poor biocompatibility of photosensitizers.
• PDT utilizes ROS, such as superoxide anion radical (O2·−), hydroxyl radical (·OH) via Type I, and singlet oxygen (1O2) via Type II, to induce cancer cell apoptosis.

Purpose of the Study:

• To develop an advanced nanoplatform for multimode PDT by integrating ultrasmall titanium dioxide nanoparticles with a heterodimer of upconversion nanoparticles and metal-organic frameworks.
• To overcome the limitations of traditional photosensitizers by enhancing ROS generation and improving biocompatibility for effective cancer therapy.

Main Methods:

• A novel nanoplatform was constructed by coating ultrasmall titanium dioxide nanoparticles onto a heterodimer composed of upconversion nanoparticles and porphyrin-based metal-organic frameworks.
• The nanoplatform was designed to utilize near-infrared light to activate upconversion nanoparticles, generating UV and visible light.
• This light emission was leveraged to stimulate photochemical reactions in titanium dioxide and porphyrin, enabling Type I and Type II PDT mechanisms.

Main Results:

• The developed nanoplatform demonstrated effective multimode PDT through both Type I and Type II ROS generation pathways.
• Near-infrared light irradiation facilitated deep-penetration PDT by activating the nanoplatform.
• The photosensitive agent exhibited good biocompatibility and potent PDT performance.

Conclusions:

• The novel nanoplatform offers a promising solution for overcoming the limitations of conventional PDT agents.
• Its ability to generate ROS through multiple pathways and its good biocompatibility position it as a versatile agent for future photodynamic therapy applications.