Dendritic cell (DC) vaccine is an effective strategy for cancer immunotherapy by carrying antigen into DCs and migrating these DCs to drain lymph nodes after inoculation. In this article, second near-infrared window (NIR-II) fluorescent nanoparticles have been used to uptake antigen and activate DCs. Ovalbumin (OVA), an antigen for immunization, can be loaded on the surface of these NIR-II fluorescent nanoparticles via electrostatic interaction by virtue of their functionalized poly(L-lysine) (PLL), which exhibits biocompatibility and strong selective interaction with OVA. In addition, these antigen-loaded complexes can efficiently be engulfed by immature DCs to induce DC maturation and cytokine secretion. After subcutaneous injection, highly sensitive NIR-II fluorescence signal from nanoparticles indicates that nanoparticle-labeled DCs can successfully migrate into lymph nodes in vivo, showing great promise in immunotherapy against cancer.

树突状细胞（DC）疫苗是一种通过将抗原带入DC并将这些DC迁移至接种后引流淋巴结的癌症免疫疗法的有效策略。在本文中，已使用第二个近红外窗口（NIR-II）荧光纳米颗粒摄取抗原并激活DC。卵白蛋白（OVA）是一种用于免疫的抗原，凭借其功能化的聚L（L-赖氨酸（PLL），具有生物相容性和与OVA的强选择性相互作用。此外，未成熟的DC可以有效地吞噬这些载有抗原的复合物，从而诱导DC成熟和细胞因子分泌。皮下注射后，来自纳米颗粒的高度敏感的NIR-II荧光信号表明，纳米颗粒标记的DC可以在体内成功迁移到淋巴结中，显示出对癌症的免疫治疗的巨大希望。