Polymeric STING Pro-agonists for Tumor-Specific Sonodynamic Immunotherapy

The efficacy of combination immunotherapy has been limited by tumor specificity and immune-related adverse events (irAEs). Herein, we report the development of polymeric STING pro-agonists (PSPA), whose sono-immunotherapeutic efficacy is activated by sono-irradiation and elevated glutathione (GSH) within the tumor microenvironment (TME). PSPA is composed of sonosensitizers (semiconducting polymer) and STING agonists (MSA-2) via the GSH-activatable linkers. Under sono-irradiation, PSPA serves as a sonosensitizer to generate O-1(2) and induce immunogenic cell death (ICD) of malignant tumor cells. Furthermore, MSA-2 is released specifically in tumor microenvironment with highly expressed GSH, minimizing off-target side effects. The activation of the STING pathway elevates the interferon-& beta; level and synergizes with SDT to enhance the anti-tumor response. Therefore, this work proposes a universal approach for spatiotemporal regulation of cancer sono-immunotherapy.

Automated summary

We report the development of polymeric STING pro-agonists (PSPA) for cancer sono-immunotherapy. PSPA is activated by sono-irradiation and elevated GSH within the tumor microenvironment (TME). Under sono-irradiation, PSPA generates O-1(2) and induces immunogenic cell death (ICD) of malignant tumor cells. Furthermore, the release of STING agonist (MSA-2) is specific to the tumor microenvironment with highly expressed GSH, minimizing off-target side effects. The activation of the STING pathway synergizes with SDT to enhance the anti-tumor response.