Induction of Tumor Ferroptosis‐Dependent Immunity via an Injectable Attractive Pickering Emulsion Gel
Xiaomeng Dai, Jia Zhang, Xuanwen Bao, Yixuan Guo, Yuzhi Jin, Chenjing Yang, Hangyu Zhang, Lulu Liu, Yang Gao, Chanqi Ye, Wei Wu, Chuan Liu, Chun‐Xia Zhao, Jianpeng Sheng, En Ren, Hongjun Li, Weijia Fang, Baiheng Wu, Jian Ruan, Zhen Gu, Dong Chen, Peng Zhao
Abstract
The combination of ferroptosis inducers and immune checkpoint blockade can enhance antitumor effects. However, the efficacy in tumors with low immunogenicity requires further investigation. In this work, a water-in-oil Pickering emulsion gel is developed to deliver (1S, 3R)-RSL-3 (RSL-3), a ferroptosis inducer dissolved in iodized oil, and programmed death-1 (PD-1) antibody, the most commonly used immune checkpoint inhibitor dissolved in water, with optimal characteristics (RSL-3 + PD-1@gel). Tumor lipase degrades the continuous oil phase, which results in the slow release of RSL-3 and PD-1 antibody and a notable antitumor effect against low-immunogenic hepatocellular carcinoma and pancreatic cancer. Intriguingly, the RSL-3 + PD-1@gel induces ferroptosis of tumor cells, resulting in antitumor immune response via accumulation of helper T lymphocyte cells and cytotoxic T cells. Additionally, the single-cell sequence profiling analysis during tumor treatment reveals the induction of ferroptosis in tumor cells together with strong antitumor immune response in ascites.