Department of Microbiology, Pasteur Institute of Iran, Tehran, Iran.
Departments of Microbiology and Mycology, Pasteur Institute of Iran, P. O. Box 13164, Tehran, Iran.
Curr Pharm Des. 2017;23(18):2665-2672. doi: 10.2174/1381612823666170112124303.
There is no doubt about the whole cell pertussis vaccine efficacy, but it is necessary to improve the vaccine quality specially to decrease its toxicity by obtaining good immunogenicity with low bacterial content. In this work, under optimum condition inactivated B. pertussis bacteria cells entrapped with alginate microparticles were fabricated and in vivo immunogenicity and ptency of new microparticle based vaccine were evaluated in mice. Microspheres loaded with inactive B. pertussis bacterium cells were prepared via an emulsification method and analyzed for morphology, size, polydispersity index, loading efficiency, loading capacity, release profile and in vivo potency. The inactivated bacterial suspension mixture prepared in this work was nontoxic and showed potent ED50 (1:333 of human dose) and preserved agglutinins 1, 2, 3. The optimum conditions for the preparation of microparticles were achieved at alginate concentration 3.8% (w/v), CaCl2 8% (w/v), PLL 0.1% (w/v), lipophilic surfactant 0.22 (%w/v), hydrophilic surfactant 3.6 (%w/v), cross linking time 3min, homogenization rate 600 rpm, and alginate to CaCl2 solution ratio 4. Both empty and B. pertussis loaded microparticles exhibited smooth surface texture and relatively spherical shape. The B. pertussis encapsulated microspheres fabricated under optimized conditions showed mean particle size 151.1 μm, polydispersity index 0.43, loading efficiency 89.6%, loading capacity 36.3%, and relatively constant release rate lasted to 15 days. In vivo immunogenicity and protection study against wild type challenge showed strongly higher potency (approximately 2.5 fold) of encapsulated B. pertussis organisms than non-encapsulated conventional aluminum hydroxide adsorbed vaccine. It can be concluded that microencapsulation of inactive B. pertussis cells appears to be a suitable approach for improving the wP vaccine quality, specially by obtaining good immunogenicity with low bacterial content.
全细胞百日咳疫苗的疗效毋庸置疑，但有必要专门提高疫苗质量，通过用低细菌含量获得良好的免疫原性来降低其毒性。在这项工作中，在最佳条件下，用海藻酸钠微球包埋失活的百日咳杆菌细胞，并在小鼠体内评估新型微球疫苗的免疫原性和效力。通过乳化法制备负载失活百日咳杆菌细胞的微球，并对其形态、粒径、多分散指数、载药量、包封率、释放曲线和体内效力进行分析。本工作中制备的失活细菌悬浮液混合物无毒，具有有效的 ED50（人类剂量的 1:333），并保留了 1、2、3 型凝集素。制备微球的最佳条件为海藻酸钠浓度 3.8%（w/v）、CaCl2 8%（w/v）、PLL 0.1%（w/v）、亲脂性表面活性剂 0.22%（w/v）、亲水性表面活性剂 3.6%（w/v）、交联时间 3min、匀浆速度 600rpm 和海藻酸钠与 CaCl2 溶液的比例为 4。空微球和负载百日咳菌的微球均表现出光滑的表面纹理和相对球形的形状。在优化条件下制备的包封有 B. pertussis 的微球平均粒径为 151.1μm，多分散指数为 0.43，载药效率为 89.6%，载药量为 36.3%，释放率相对恒定，持续 15 天。体内免疫原性和对野生型攻击的保护研究表明，包封的 B. pertussis 生物比非包封的传统氢氧化铝吸附疫苗具有更强的效力（约 2.5 倍）。可以得出结论，失活 B. pertussis 细胞的微囊化似乎是一种提高 wP 疫苗质量的合适方法，特别是通过用低细菌含量获得良好的免疫原性。
