Ultrasound-Triggered Nanogel Boosts Chemotherapy and Immunomodulation in Colorectal Cancer

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Chemotherapy is a primary treatment for colorectal cancer but faces limitations due to chemoresistance.
• Chemoresistance in colorectal cancer is often linked to poor drug accumulation within tumors and an immunosuppressive tumor microenvironment.

Purpose of the Study:

• To develop a novel low-intensity ultrasound (LIU)-controlled, charge-reversible nanogel (R-NG) for enhanced colorectal cancer chemotherapy.
• To improve intratumoral drug accumulation and reverse the immunosuppressive tumor microenvironment.

Main Methods:

• Synthesized oxaliplatin-loaded, charge-reversible nanogels (Oxa-R-NGs) using chitosan-polypyrrole polymers and TiO2 nanoparticles.
• Utilized the acidic tumor environment for charge conversion and low-intensity ultrasound (LIU) to trigger drug release and ROS generation.
• Investigated the nanogel's effect on tumor-associated macrophage polarization.

Main Results:

• Oxa-R-NGs exhibited charge conversion in acidic tumor environments, enhancing tumor penetration and cellular uptake.
• LIU stimulation of intratumoral Oxa-R-NGs led to sustained reactive oxygen species (ROS) generation.
• ROS generation disrupted nanogel bonds, releasing oxaliplatin and modulating macrophage polarization, thereby overcoming chemoresistance.

Conclusions:

• The developed Oxa-R-NG system effectively enhances oxaliplatin delivery and overcomes chemoresistance in colorectal cancer.
• The combination of charge-reversible nanogels, LIU, and ROS generation offers a promising strategy for synergistic cancer therapy.
• This approach addresses key challenges in colorectal cancer treatment by improving drug accumulation and modulating the tumor immune microenvironment.