Improving STING Agonist Delivery for Cancer Immunotherapy Using Biodegradable Mesoporous Silica Nanoparticles.

Stimulator of interferon genes (STING) activation by intratumoral STING agonist treatment has been recently shown to eradicate tumors in preclinical models of cancer immunotherapy, generating intense research interest and leading to multiple clinical trials. However, there are many challenges associated with STING agonist-based cancer immunotherapy, including low cellular uptake of STING agonists. Here, biodegradable mesoporous silica nanoparticles (bMSN) with an average size of 80 nm are developed for efficient cellular delivery of STING agonists. STING agonists delivered via bMSN potently activate innate and adaptive immune cells, leading to strong antitumor efficacy and prolonged animal survival in murine models of melanoma. Delivery of immunotherapeutic agents via biodegradable bMSN is a promising approach for improving cancer immunotherapy.