Multifunctional Oxygen-Generating Nanoflowers for Enhanced Tumor Therapy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Tumor hypoxia significantly limits the effectiveness of cancer therapies like chemotherapy and sonodynamic therapy (SDT).
• Developing strategies to overcome tumor hypoxia is crucial for enhancing therapeutic outcomes.

Purpose of the Study:

• To create a tumor microenvironment-responsive nanoplatform (SMPC&D) for synergistic chemotherapy and SDT in hypoxic tumors.
• To investigate the hypoxia-alleviating and therapeutic effects of the SMPC&D nanoplatform.

Main Methods:

• Fabrication of SiO2-MnO2-PEG-Ce6&DOX (SMPC&D) nanoparticles encapsulating MnO2, PEG, Chlorin e6 (Ce6), and doxorubicin (DOX).
• Evaluation of physicochemical properties and *in vitro*/*in vivo* therapeutic efficacy under ultrasound stimulation.
• Assessment of hypoxia relief via GSH-triggered biodegradation and MnO2-catalyzed O2 generation.

Main Results:

• SMPC&D nanoparticles effectively alleviated tumor hypoxia by depleting GSH and generating oxygen.
• Ultrasound stimulation enhanced drug release, cellular uptake, and chemotherapy efficacy by downregulating P-gp expression.
• The nanoplatform demonstrated improved synergistic therapeutic effects for hypoxic tumors *in vitro* and *in vivo*.

Conclusions:

• The biodegradable SMPC&D nanoplatform offers a promising strategy for synergistic chemotherapy and SDT in hypoxic tumors.
• Targeting tumor hypoxia is key to enhancing the efficacy of combined cancer therapies.