Cascade-activatable NO release based on GSH-detonated "nanobomb" for multi-pathways cancer therapy

Area of Science:

• Biomedical Engineering
• Nanomedicine
• Cancer Therapy

Background:

• Photodynamic therapy (PDT) combined with adjuvant treatments offers a promising strategy for cancer therapy.
• Tumor hypoxia remains a significant challenge, limiting the efficacy of conventional treatments like PDT.
• Developing novel nanocarriers for synergistic therapies is crucial for improving treatment outcomes.

Purpose of the Study:

• To develop a glutathione (GSH)-responsive
• nanobomb
• for synergistic photodynamic and gas therapy (PDT-GT).
• To investigate the efficacy of the nanobomb in enhancing anti-tumor immune responses and overcoming tumor hypoxia.
• To evaluate the potential of this nanobomb strategy for clinical translation in treating solid tumors.

Main Methods:

• Simultaneous encapsulation of methylene blue (MB) and L-arginine (L-Arg) into PEG-modified mesoporous organosilicon nanoparticles (MON).
• Pharmacokinetic studies in mice to assess blood circulation, bioavailability, and tumor accumulation.
• In vitro and in vivo evaluation of reactive oxygen species (ROS) and nitric oxide (NO) generation under laser irradiation.
• Assessment of cancer cell apoptosis, cell-cycle arrest, and anti-tumor immune responses.

Main Results:

• The L-Arg/MB@MP nanobomb exhibited prolonged circulation, enhanced tumor accumulation, and efficient ROS generation for PDT.
• Co-generation of NO from L-Arg amplified therapeutic effects and alleviated tumor hypoxia.
• Synergistic PDT-GT induced immunogenic cell death, G2/M cell-cycle arrest, and apoptosis in cancer cells.
• GSH-depletion in tumors enhanced the combined therapeutic efficacy.

Conclusions:

• The developed "nanobomb" strategy effectively integrates PDT and GT for synergistic anti-tumor effects.
• This approach shows potential for overcoming tumor hypoxia and enhancing anti-tumor immunity.
• The GSH-responsive nanobomb offers a novel platform for treating hypoxic solid tumors with improved clinical translation prospects.