Engineered g-C₃N₄ Quantum Dots for Tunable Two-Photon Imaging and Photodynamic Therapy

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Complex multi-component systems hinder NIR-light-triggered diagnostic and therapeutic applications.
• Developing single-component nanoplatforms with dual functionality is crucial for advancing biomedical applications.

Purpose of the Study:

• To develop a single-component dual-functional nanoplatform for near-infrared (NIR) light-triggered two-photon imaging (TPI) and two-photon excited photodynamic therapy (TPE-PDT).
• To engineer graphitic carbon nitride quantum dots (g-C3N4 QDs) with tunable capabilities for TPI and TPE-PDT.

Main Methods:

• Synthesized three types of engineered g-C3N4 QDs (CN, CN-DPT, CN-THDT) via copolymerization of melamine with selected monomers.
• Evaluated in vitro cytotoxicity and biocompatibility of the synthesized QDs.
• Assessed TPI and TPE-PDT performance under an 800 nm NIR laser.

Main Results:

• All synthesized g-C3N4 QDs demonstrated excellent biocompatibility and tumor cell delivery.
• CN-DPT QDs exhibited a strong TPI signal and efficient reactive oxygen species (ROS) generation for TPE-PDT under NIR laser irradiation.
• The single-component CN-DPT QDs effectively performed dual-functional TPI and TPE-PDT.

Conclusions:

• Engineered g-C3N4 QDs offer a stable, biocompatible, single-component platform for dual-modal TPI and TPE-PDT.
• These findings suggest potential for g-C3N4-based nanomaterials as novel theranostic agents in cancer treatment.
• The developed nanoplatform overcomes limitations of complex multi-component systems.