Enhancing Immune Responses and Tumor Inhibition with Iron Oxide Nanoparticle Adjuvants

Adjuvants are essential for enhancing vaccine-induced immune responses, yet the number of approved adjuvants remains limited, which necessitates the development of safe, and effective options. This study identifies iron oxide nanoparticles (IONPs) as potent activators of the NF-κB and IRF signaling pathways, suggesting their potential as adjuvants. IONPs were found to promote dendritic cell maturation and activation, enhance IgG expression, and stimulate robust Th1/Th2 immune responses in mice. Furthermore, IONPs induced the proliferation of CD8 + T cells and germinal center B cells, contributing to a durable humoral immune response. Importantly, IONPs demonstrated efficacy in preventing and treating B16F10 tumors in mice. These findings position IONPs as promising candidates for future adjuvant development.