Heterojunction engineered bioactive chlorella for cascade promoted cancer therapy

Area of Science:

• Biomedical Engineering
• Materials Science
• Cancer Therapy

Background:

• Tumor hypoxia limits photodynamic therapy (PDT) efficacy.
• Developing novel strategies to enhance PDT is crucial for cancer treatment.

Purpose of the Study:

• To create a synergistic therapeutic system using Chlorella and black phosphorus nanosheets.
• To overcome tumor hypoxia and improve anti-tumor effects through combined therapies.

Main Methods:

• Functionalizing Chlorella (Chl) with black phosphorus nanosheets (BPNSs) using a "Lego building method" with polyaspartic acid and Fe3+.
• Utilizing the photosynthetic and metabolic capabilities of Chl to alleviate hypoxia and modulate immune responses.
• Constructing a type-II heterojunction between Chl and BPNSs for enhanced reactive oxygen species (ROS) generation and oxygen evolution.
• Employing Fe3+ to mediate chemodynamic therapy (CDT) by consuming glutathione and catalyzing Fenton reactions.

Main Results:

• The Chl@BP-Fe system effectively ameliorated tumor hypoxia.
• Enhanced infiltration, proliferation, and maturation of immune cells were observed.
• Improved light conversion efficiency led to increased singlet oxygen (1O2) and oxygen (O2) production.
• Synergistic photodynamic, chemodynamic, and immune therapeutic effects were achieved, demonstrating significant anti-tumor activity.
• The material exhibited good biocompatibility and biodegradability.

Conclusions:

• Photosynthesis-enhanced synergistic therapy using Chlorella and black phosphorus nanosheets is a promising strategy against tumors.
• This approach effectively addresses tumor hypoxia and stimulates anti-tumor immunity.
• The developed Chl@BP-Fe system holds potential for clinical applications in cancer treatment.