Sono-Immunotherapy Mediated Controllable Composite Nano Fluorescent Probes Reprogram the Immune Microenvironment of Hepatocellular Carcinoma

BACKGROUND: Despite the clinical efficacy of immunotherapy in treating malignant tumors, its effectiveness is often hampered by the immunosuppressive nature of the tumor microenvironment (TME). In this study, we propose the design of a nanoscale ultrasound contrast agent capable of triggering macrophage polarization and immunogenic cell death (ICD) for the treatment of hepatocellular carcinoma (HCC) through sonodynamic treatment (SDT) and immunotherapy. METHODS: The re-educator (designated as ICG@C3F8-R848 NBs) is composed of the Toll-like receptor agonist resiquimod (R848) and the sonosensitizer Indocyanine green (ICG), utilizing nanobubbles (NBs) as carriers. The technique known as ultrasound-targeted nanobubble destruction (UTND) employs nanosized microbubbles and low-frequency ultrasound (LFUS) to ensure accurate drug delivery and enhance safety. RESULTS: Following intravenous delivery, ICG@C3F8-R848 NBs have the potential to selectively target and treat primary tumors using SDT in conjunction with ultrasonography. Importantly, R848 can enhance antitumor immunity by inducing the polarization of macrophages from an M2 to an M1 phenotype. CONCLUSION: The SDT-initiated immunotherapy utilizing ICG@C3F8-R848 NBs demonstrates significant tumor suppression effects with minimal risk of systemic toxicity. The utilization of this self-delivery re-education technique would contribute to advancing the development of nanomedicine for the treatment of hepatocellular carcinoma.