肿瘤微环境的逐步揭示使得肿瘤逐渐被认为是一个异常器官，而非仅是恶性细胞群落。肿瘤特殊的代谢模式决定了氧化应激是肿瘤微环境最重要的属性之一。鉴于活性氧簇(ROS)几乎贯穿众多已知肿瘤耐受机制，精准靶向清除肿瘤微环境ROS不失为“釜底抽薪”之策。本项目拟结合纳米黑色素高效ROS清除能力及免疫细胞定向趋化效应，构建一种黑色素化免疫细胞（黑细胞），其可跨越体内及肿瘤微环境屏障，精准靶向调控肿瘤氧化应激微环境，降低肿瘤抗凋亡特性，为光热杀伤创造最佳条件。前期探索已初步建立钙离子介导的生物相容性黑细胞构筑方法。本项目拟进一步深入探究黑细胞组装过程及活细胞表面黑色素生长机制。验证黑细胞兼具ROS清除及趋化靶向两大关键能力。体内注射后，考察黑细胞长循环、肿瘤富集及渗透能力，继而靶向调控肿瘤氧化应激，抑制抗凋亡蛋白表达，促光热杀伤肿瘤。本项目研究有望为肿瘤微环境调控提供新思路，产出具有临床转化潜力的新技术。

The complexity of tumor microenvironment revealed that tumor is an abnormal organ composed of different cell communities. Oxidative stress is one of the most important basic properties of tumor microenvironment determined by the specific metabolic pattern of tumor. In view of the unique role of reactive oxygen species (ROS) in many important tumor tolerance mechanisms and invasive behaviors, it is a "promising" strategy to develop efficient and accurate target strategy to clear the ROS in tumor microenvironment. In this project, a kind of melanized immune cells (hereinafter referred to as: black cells) is constructed. By employing the ROS scavenging ability of melanin and the directional chemotactic effect of immune cells, the black cell could across the systematic and tumor microenvironment barrier and regulate the ROS state of tumor precisely. The regulated tumor microenvironment will establish the optimized condition for the following photothermal therapy. The method for the construction of biocompatible black cells has been preliminarily established by the mediation of calcium ions. The assembly process of the black cell and the growth mechanism of melanin on living cells will be further explored. The in vitro ROS scavenger and chemotaxis abilities and in vivo long circulation, tumor targeting, infiltration, ROS regulation and finally the tumor inhibition abilities of black cell will also be verified. This project aims to not only provide a novel strategy for the regulation of tumor microenvironment, but also to pave the new route for vaccine development and hold the clinic impact.