NIR responsive nanosystem based on upconversion nanoparticle-engineered bacteria for immune/photodynamic combined...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Engineered bacteria show potential for targeted tumor therapy, but live bacteria pose infection risks and blue light activation limits tissue penetration.
• Current methods lack efficient bacterial clearance post-therapy and safe, deep-tissue activation strategies.

Purpose of the Study:

• To develop a nanoplatform for dual-wavelength activation and near-infrared (NIR) controlled self-clearance of engineered bacteria for enhanced tumor therapy.
• To overcome the limitations of blue light penetration and safety concerns associated with live bacteria in tumor treatment.

Main Methods:

• Development of a nanoplatform combining dual-emission upconversion nanoparticles (DDUCNPs) with engineered bacteria.
• Utilized 980 nm light for DDUCNP-mediated blue light conversion to activate bacteria and release tumor necrosis factor-alpha (TNF-α).
• Employed 808 nm light for DDUCNP-mediated red light conversion to activate photosensitizers, generate reactive oxygen species (ROS) for bacterial clearance and photodynamic therapy (PDT).

Main Results:

• The nanoplatform successfully achieved bacteria activation and controlled release of TNF-α for tumor ablation under NIR light.
• Engineered bacteria were effectively cleared in vivo via ROS generation triggered by NIR light, minimizing infection risks.
• Simultaneous PDT enhanced tumor treatment efficacy, demonstrating a synergistic therapeutic effect.

Conclusions:

• The developed nanoplatform enables precise, NIR-triggered activation and self-clearance of engineered bacteria, offering a safer and more effective tumor therapy strategy.
• This approach overcomes blue light penetration limitations and addresses safety concerns of live bacteria, paving the way for advanced cancer treatment.