纳米粒子介导的肿瘤疫苗在肿瘤术后的辅助治疗中有着广阔的应用前景，但仍然存在所携带抗原比较单一，靶向性不佳以及抗原递呈细胞对所携带的抗原的摄取，处理和递呈效率低等问题。在本项目中，我们首先合成包裹CpG-ODN的，聚多巴胺改性的聚乳酸-羟基乙酸（PLGA）纳米粒子。该纳米粒子可以在中性环境下，保持稳定，但在微酸性环境下，化学键结合蛋白质抗原。在此基础上，在该纳米粒子表面化学修饰E选择素，使其可以在不影响中性粒细胞正常生理功能的前提下，锚定在中性粒细胞表面，得到基于中性粒细胞的抗原捕捉系统。该系统可以在血液循环过程中保持稳定，但在随中性粒细胞到达术后炎症微酸性环境后，高效捕捉由于手术而暴露的多种肿瘤蛋白质抗原，而捕捉的抗原能被抗原递呈细胞高效摄取，处理和递呈，产生大量的杀伤性和记忆性T细胞，抑制肿瘤术后的转移和复发。该基于中性粒细胞的抗原捕捉系统为基于纳米粒子的个体化免疫治疗提供新思路。

Nanoparticle-mediated tumor vaccine has great potentials in post-surgical adjuvant therapy. However, the highly variable and limited scope of delivered antigens, the poor targeting efficiency as well as the restricted functions of antigen-presenting cells limit the anti-tumor outcome. Here we will fabricate a polydopamine modified poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing CpG-ODN (PDA-PLGA/CpG-ODN), which will show great stabilities in neutral environment but strong ability of binding protein antigens via schiff base in mild acidic environment. Further, the PDA-PLGA/CpG-ODN nanoparticle will be chemically modified with E-selectin and anchored onto the surface of neutrophil to develop an antigen-capturing system based on neutrophil, which will be endowed with the antigen-capturing ability of PDA-PLGA/CpG-ODN nanoparticle and the intact functions of neutrophil. This system will keep stable during blood circulation, but capture the tumor protein antigens once it accumulated in the mild acidic surgical bed via the inflammatory chemotaxis of neutrophil. Moreover, the antigens captured by antigen-capturing system could be effectively uptaken, processed and presented to T cell by antigen-presenting cells via efferocytosis, which is going to elicit a robust immune response, thus inhibiting the post-surgical tumor recurrence and metastasis. Our work presents a novel strategy towards personalized and nanoparticle-mediated immune therapy.