Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300192, China.
Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300192, China.
Carbohydr Polym. 2019 Nov 15;224:115172. doi: 10.1016/j.carbpol.2019.115172. Epub 2019 Aug 9.
Chitosan/calcium phosphate nanosheet as a promising antigen carrier was prepared via the direct mixture of modified chitosan, PBS and CaCl. Specifically, chitosan was modified with catechol groups, and its water solubility under neutral conditions was improved. Then, nanosheet was formed by mixing modified chitosan and PBS followed by addition of CaCl. Antigen was entrapped into the nanosheet via coprecipitation during its preparation. The nanosheet composed of CaHPO·2HO crystals, was internalized by dendritic cells (DCs) via macropinocytosis with enhanced efficiency. The antigen endosomal escape induce by nanosheet was successful observed with intracellular Lysotracker and Lamp-1 staining. Moreover, DCs activation was triggered by the nanosheet along with the up-regulated expression of co-stimulation marker and production of Th1-type cytokines. More importantly, cross-presentation of antigens achieved by the nanosheet was markedly increased when compared to free antigen. Therefore, chitosan/calcium phosphate nanosheet could be used as a vaccine carrier for effective cross-presentation of exogenous antigens.
壳聚糖/磷酸钙纳米片作为一种很有前途的抗原载体，是通过将改性壳聚糖、PBS 和 CaCl 直接混合制备得到的。具体来说，壳聚糖被儿茶酚基团修饰，从而提高了其在中性条件下的水溶性。然后，通过混合改性壳聚糖和 PBS 形成纳米片，随后加入 CaCl。在制备过程中通过共沉淀将抗原包埋在纳米片中。纳米片由 CaHPO·2HO 晶体组成，通过巨胞饮作用被树突状细胞（DC）内化，效率得到提高。通过细胞内 Lysotracker 和 Lamp-1 染色成功观察到纳米片诱导的抗原内体逃逸。此外，纳米片还能触发 DC 的激活，同时上调共刺激标志物的表达和 Th1 型细胞因子的产生。更重要的是，与游离抗原相比，纳米片介导的抗原交叉呈递明显增加。因此，壳聚糖/磷酸钙纳米片可用作疫苗载体，有效递呈外源性抗原。
