NIR-II Photoactivatable Cobalt(III) Nanoparticles for Photoactivated Metal Chemo-Immunotherapy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Therapy

Background:

• Photoactivated cobalt(III) (Co(III)) complexes show promise in cancer therapy but face limitations due to toxicity and lack of spatial-temporal control.
• Developing targeted therapies with improved control is crucial for clinical application.

Purpose of the Study:

• To develop and evaluate novel second near-infrared window (NIR-II) photoactivated cobalt(III) nanoparticles (NanoCo) for cancer treatment.
• To investigate NanoCo's efficacy, mechanisms of action, and synergistic effects with other therapies.

Main Methods:

• Synthesis of Co(III) nanoparticles (NanoCo) activated by NIR-II light (1064 nm).
• Evaluation of NanoCo's photothermal effect, cytotoxicity against platinum-resistant and sensitive cancer cells (A549DDP, CT26).
• Assessment of NanoCo's ability to induce immunogenic cell death and anti-tumor immune responses.
• Combination therapy with Pt(IV) nanoparticles (HSA@Pt) in a 4T1 tumor-bearing mouse model.

Main Results:

• NanoCo generates photothermal heat under 1064 nm irradiation, facilitating Co(III) to Co(II) reduction.
• NanoCo exhibits significantly enhanced efficacy against platinum-resistant A549DDP cells (166x cisplatin) and CT26 cells (5000x oxaliplatin).
• NanoCo triggers immunogenic cell death, enhances dendritic cell maturation, and stimulates anti-tumor immunity.
• Combination therapy with HSA@Pt and NanoCo achieved 99% tumor growth inhibition in a 4T1 mouse model.

Conclusions:

• NIR-II photoactivated NanoCo offers a promising strategy for targeted cancer therapy with improved spatial-temporal control.
• NanoCo demonstrates potent anti-tumor activity, induces immunogenic cell death, and potentiates anti-tumor immune responses.
• The combination of NanoCo and HSA@Pt shows significant therapeutic potential for overcoming tumor resistance and enhancing treatment outcomes.