摘要Immunotherapy with interleukin-2(IL-2)in treating cancers is subject to several limitations such as systemic side effects and reduced efficacy against tumors with low immune cell infiltration despite its promise.To address these challenges,IL-2-So-Lipo,a novel liposomal formulation combining IL-2 with sorafenib derivative,was developed as an anti-angiogenic drug that inhibits the growth of new blood vessels which play crucial roles in tumor growth.Sorafenib derivatives could target at melanoma-specific receptors,further enhancing liposomal specificity at the tumor site.Our results demonstrated that the prepared IL-2-So-Lipo significantly enhanced anti-tumor activity compared to IL-2 or sorafenib monotherapies,as well as their combination.In a B16F10 melanoma model,IL-2-So-Lipo was found to significantly inhibit tumor progression(tumor volume of 108.01±62.99 mm3)compared to the control group(tumor volume of 1,397.13±75.55 mm3),improving the therapeutic efficacy.This enhanced efficacy is attributed to the targeted delivery of IL-2 which promoted the infiltration and activation of cytotoxic T lymphocytes.Additionally,liposomal encapsulation of sorafenib derivatives enhanced its delivery efficiency,promoting tumor cell apoptosis and suppressing angiogenesis.Mechanistically,IL-2-So-Lipo could kill tumors by inducing a shift towards an anti-tumor immune response via facilitating the polarization of macrophages towards the M1 phenotype.Furthermore,IL-2-So-Lipo downregulated several key proteins in the MAPK signaling pathway,exerting a significant role in mediating tumor resistance to sorafenib.These findings underscore the potential of IL-2-So-Lipo as a promising strategy to improve the therapeutic efficacy of immunotherapy and targeted therapy in cancers.Moreover,the combination of IL-2 and sorafenib in a liposomal delivery system overcame the limitations of conventional IL-2 therapy,offering a synergistic approach to improve therapeutic outcomes for solid tumors.