In Situ biomimetic Nanoformulation for metastatic cancer immunotherapy

Metastasis is the leading cause of death in cancer patients. Eliciting anti-tumor immune responses against lung metastasis is hindered by the immunosuppressive microenvironment. This study explored a biomimetic nanoformulation, comprising a nanovaccine (OP) that delivers tumor antigens and adjuvants spatially and temporally in a virus-like manner, and a pulmonary surfactant-biomimetic liposome with an immunomodulator, JQ1 (PS-JQ1). The findings of this study showed that intratracheal administration of OP+PS-JQ1 activated lung immune cells without concomitant excess inflammation, enhanced tumor antigen cross-presentation, generated a significantly high antigen-specific CD8+ T cell response, and reshaped the immunocellular composition in B16 melanoma tumor-bearing lung. OP+PS-JQ1 nanoformulation exhibited a striking immunotherapeutic efficacy, induced local and systemic tumor suppression, improved survival of mice, initiated immune memory that prevents recurrence of secondary tumors. This stable and nontoxic nanoformulation provides a simple, flexible, and robust strategy for augmenting anti-tumor immunity for metastatic cancer.