Jia Jilei, Liu Qi, Yang Tingyuan, Wang Lianyan, Ma Guanghui
State Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
J Mater Chem B. 2017 Feb 28;5(8):1611-1623. doi: 10.1039/c6tb02845d. Epub 2017 Feb 6.
Functional calcium carbonate (CaCO) particles of micron and submicron sizes used in catalysis and biomedicine have attracted considerable attention for decades. In this paper, the process parameters for CaCO crystallization were systematically investigated. Our experimental results demonstrated the significance of temperature during fabrication. Under the optimized conditions, various uniform-sized and spherical CaCO microparticles (MPs) with average diameters from 0.8 μm to 5 μm were facilely and rapidly fabricated via different mixing strategies including mechanical stirring, homogenization, and ultrasonication. The physicochemical characteristics of the CaCO microspheres were evaluated. And, the hepatitis B surface antigen (HBsAg) used as a model antigen was encapsulated into the particles (1 μm and 4 μm) for investigating the immune responses elicited after vaccination. In vitro, dendritic cells (DCs) were significantly activated by the MP-based vaccine formulations with up-regulated co-stimulatory molecules expression of CD40 and CD83. After immunization, CaCO MPs loaded with HBsAg induced greater lymphocyte activation, more cytokine secretion, higher antigen-specific IgG titers and more memory T cell generation to protect against reinfection. Therefore, the CaCO MPs, especially the 1 μm particles, could induce strong cellular and humoral immune responses, probably because of easier uptake and more efficient antigen-presentation by DCs. With the advantages of good biocompatibility, high loading capacity and easy preparation, they could be potentially useful as vaccine adjuvants. These results might provide further design principles for potent inorganic particulate adjuvant and delivery systems.
用于催化和生物医学的微米级和亚微米级功能性碳酸钙（CaCO）颗粒几十年来一直备受关注。本文系统研究了CaCO结晶的工艺参数。我们的实验结果证明了制备过程中温度的重要性。在优化条件下，通过机械搅拌、均质化和超声处理等不同混合策略，轻松快速地制备出了平均直径为0.8μm至5μm的各种尺寸均匀的球形CaCO微颗粒（MPs）。对CaCO微球的物理化学特性进行了评估。并且，将用作模型抗原的乙肝表面抗原（HBsAg）包封到颗粒（1μm和4μm）中，以研究接种疫苗后引发的免疫反应。在体外，基于MP的疫苗制剂显著激活了树突状细胞（DCs），CD40和CD83的共刺激分子表达上调。免疫后，负载HBsAg的CaCO MPs诱导了更强的淋巴细胞激活、更多的细胞因子分泌、更高的抗原特异性IgG滴度以及更多的记忆T细胞生成，以防止再次感染。因此，CaCO MPs，尤其是1μm的颗粒，可能因其易于被DCs摄取和更有效的抗原呈递而诱导强烈的细胞免疫和体液免疫反应。由于具有良好的生物相容性、高负载能力和易于制备的优点，它们有可能用作疫苗佐剂。这些结果可能为有效的无机颗粒佐剂和递送系统提供进一步的设计原则。
