A Self-Evaluating Photothermal Therapeutic Nanoparticle

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Current tumor therapy and evaluation methods are separate and lack real-time feedback.
• Existing imaging techniques cannot assess tumor-therapeutic effects dynamically.
• There is a critical need for theranostic strategies enabling real-time therapeutic efficiency assessment.

Purpose of the Study:

• To develop an intelligent nanoparticle for simultaneous photothermal therapy (PTT) and real-time therapeutic effect evaluation.
• To design a near-infrared fluorescent probe (Cy-CBT-NP) responsive to PTT and tumor microenvironment.
• To enable fluorescence "Turn-On" for monitoring PTT efficacy in vitro and in vivo.

Main Methods:

• Rational design of a small molecular near-infrared probe (Cy-CBT) incorporating a photothermal agent and caspase-3 substrate.
• Facile preparation of intelligent nanoparticles (Cy-CBT-NP) via a CBT-Cys click condensation reaction.
• Utilizing fluorescence "Turn-On" mechanism triggered by caspase-3 cleavage for real-time monitoring of PTT-induced cell death.

Main Results:

• Developed Cy-CBT-NP with quenched fluorescence that becomes "On" upon caspase-3 (Casp3) cleavage.
• Demonstrated Cy-CBT-NP's ability to evaluate PTT efficiency in real time at cellular and tumor levels.
• Confirmed photothermal responsiveness and disassembly of the nanoparticle in response to the tumor microenvironment.

Conclusions:

• The developed Cy-CBT-NP serves as a theranostic agent for PTT and real-time therapeutic evaluation.
• This smart nanoparticle strategy shows promise for improving solid tumor treatment monitoring.
• The "Turn-On" fluorescence mechanism provides a novel approach for assessing treatment efficacy dynamically.