Dual-Physical-Field Nanocatalysis: Injectable Hydrogel Enables Piezo-Photothermal Synergy for Breast Cancer Therapy.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Therapy

Background:

• Piezocatalytic therapy (PCT) shows promise for cancer treatment by generating reactive oxygen species (ROS) from mechanical energy.
• Limitations of PCT include rapid electron-hole recombination and poor retention within tumors.
• Combining PCT with other modalities like photothermal therapy (PTT) can enhance efficacy.

Purpose of the Study:

• To develop an injectable, conductive, thermosensitive hydrogel for enhanced piezocatalytic and photothermal breast cancer therapy.
• To engineer BiOCl@CuO nanosheets for improved charge separation and ROS generation.
• To evaluate the synergistic therapeutic effects and immune response in vitro and in vivo.

Main Methods:

• Fabrication of heterostructured BiOCl@CuO nanosheets.
• Incorporation of nanosheets into a Pluronic F127 (F127) and reduced graphene oxide (rGO) hydrogel.
• Combination therapy using ultrasound (US) for piezocatalysis and near-infrared (NIR) irradiation for PTT.
• In vitro and in vivo evaluation of therapeutic efficacy, cell death pathways, and immune activation.

Main Results:

• The BiOCl@CuO/F127@rGO hydrogel demonstrated efficient ROS generation under US and heat generation under NIR irradiation.
• In vitro studies showed 60% breast cancer cell ablation with minimal toxicity to normal cells.
• In vivo studies resulted in 90% tumor regression, reduced proliferation and angiogenesis, and induced apoptosis and immunogenic cell death.
• Significant immune activation was observed, including increased CD8+ T cell infiltration and IFN-γ secretion.

Conclusions:

• The developed hydrogel system offers a precise, minimally invasive strategy for combined piezocatalysis and photothermal therapy in breast cancer.
• The synergistic approach enhances ROS production, thermal ablation, and stimulates a potent anti-tumor immune response.
• This platform holds potential for advanced combination cancer therapies.