Supplementary file 1_EGCG and DOX dual-drug-loaded enzyme-responsive nanovesicles boost mitochondrial-mediated ICD for improved immunotherapy.docx

Enhancing cancer immunotherapy using methods that induce immunogenic cell death (ICD) can significantly improve its effectiveness and profoundly influence its role as a highly efficient cancer treatment strategy. However, the limited penetration of cytotoxic T cells into tumors, owing to dense tumor fibrosis, remains a significant barrier to immunotherapy. A tumor microenvironment-sensitive intelligent dual-drug delivery system was developed to simultaneously deliver epigallocatechin-3-gallate (EGCG) and doxorubicin (DOX) to mitochondria. EGCG enhanced the mitochondria-targeted action of DOX and increased damage to the mitochondrial electron transport chain which facilitated capturing electrons in the mitochondrial matrix of DOX. Subsequently, DOX molecules form a semiquinone intermediate and electrons are transferred to oxygen to generate reactive oxygen species (ROS) that induce mitochondrial apoptosis. These results indicate that EGCG amplifies the combined effects of chemo/chemodynamic therapy of DOX, demonstrating a pronounced synergistic ICD effect that recruits CD8+ T cells to the tumor microenvironment (TME). In addition, EGCG promotes T-cell infiltration into tumor tissues by inhibiting the transforming growth factor-β signaling pathway, thereby significantly enhancing antitumor efficacy. This study advances the efficacy of immunotherapy through bidirectional synergy, which not only enhances intrinsic tumor immunogenicity but also overcomes the extrinsic physical barriers of tumors, providing a new direction for the development of broadly applicable immunotherapies.

采用诱导免疫原性细胞死亡（immunogenic cell death, ICD）的方法增强癌症免疫治疗，可显著提升治疗效果，并深刻强化其作为高效癌症治疗策略的应用价值。然而，致密的肿瘤纤维化会阻碍细胞毒性T细胞向肿瘤内部浸润，仍是免疫治疗面临的重大障碍。本研究开发了一种肿瘤微环境响应型智能双药递送系统，可将表没食子儿茶素没食子酸酯（EGCG）与阿霉素（DOX）同时递送至线粒体。EGCG可增强DOX的线粒体靶向作用，并加重其对线粒体电子传递链的损伤，这一过程可捕获DOX线粒体基质内的电子。随后，DOX分子会形成半醌中间体，电子随后被转移至氧分子以产生活性氧（ROS），进而诱导线粒体凋亡。上述结果表明，EGCG可放大DOX的化学/化学动力学联合治疗效果，展现出显著的协同免疫原性细胞死亡效应，可将CD8+ T细胞招募至肿瘤微环境（TME）中。此外，EGCG可通过抑制转化生长因子-β信号通路，促进T细胞向肿瘤组织内浸润，从而显著提升抗肿瘤疗效。本研究通过双向协同策略提升了免疫治疗的效果，不仅增强了肿瘤内在免疫原性，还克服了肿瘤外在物理屏障，为开发广谱适用的免疫治疗手段提供了全新方向。