Hepatocellular carcinoma (HCC) is a highly malignant tumor that is resistant to chemotherapy and immunotherapy. Icaritin (ICT), a traditional Chinese medicine, has been reported as an immunoregulatory agent for treating advanced unresectable HCC. ICT induces mitophagy to cause immunogenic cell death (ICD); however, the poor bioavailability of ICT limits its therapeutic efficacy and clinical use. Therefore, this study aimed to assess the effect of using the poly(2-(N-oxide-N,N-diethylamino) ethyl methacrylate)-b-poly(ε-caprolactone) copolymer (OPDEA-PCL) to encapsulate ICT into nanoparticles (ICT NPs). OPDEA-PCL/ICT NPs colocalized with the mitochondria, promoting the ICD induction effect of ICT in mouse HCC H22 cells. In the H22 subcutaneous tumor model, intravenously injected OPDEA-PCL/ICT NPs quickly accumulated in the tumor and efficiently activated systemic anticancer immunogenicity through their effects on mitophagy. The resulting tumor suppression rate was 60%, which was significantly higher than that of free ICT and poly(ethylene glycol) (PEG)-PCL/ICT NPs. Furthermore, mouse survival was also prolonged by nearly 2-fold with OPDEA-PCL/ICT NPs compared with PBS. In summary, this approach provides valuable insights into improving the immunotherapeutic efficacy of ICT for HCC.

Keywords: cancer immunotherapy; hepatocellular carcinoma; icaritin; immunogenic cell death; mitochondria-targeted nanoparticles; mitophagy.

肝细胞癌（HCC）是一种对化疗和免疫疗法具有抗性的高度恶性肿瘤。伊卡替宁（ICT），一种传统中药，已被报道作为调节晚期不可切除的HCC治疗的免疫调节剂。ICT通过诱导线粒体自噬来引起免疫原性细胞死亡（ICD），但ICT较差的生物利用度限制了其疗效和临床应用。因此，本研究旨在评估使用聚(2-(N-氧化-N,N-二乙基氨基)乙基甲丙烯酸酯)-b-聚(ε-己内酯)(OPDEA-PCL)共聚物封装ICT制成纳米颗粒（ICT NPs）的效果。OPDEA-PCL/ICT NPs与线粒体共定位，在小鼠HCC H22细胞中促进了ICT的ICD诱导效应。在H22皮下肿瘤模型中，静脉注射OPDEA-PCL/ICT NPs快速积聚于肿瘤内，并通过其对线粒体自噬的影响有效激活全身抗癌症免疫原性。由此产生的肿瘤抑制率为60%，显著高于游离ICT和聚(乙二醇) (PEG)-PCL/ICT NPs的水平。此外，与PBS相比，使用OPDEA-PCL/ICT NPs的小鼠生存期也延长了近2倍。总之，这种方法为提高HCC中ICT免疫治疗疗效提供了有价值的见解。

关键词：癌症免疫疗法；肝细胞癌；伊卡替宁；免疫原性细胞死亡；线粒体靶向纳米颗粒；线粒体自噬。