Singh M, Singh A, Talwar G P
National Institute of Immunology, New Delhi, India.
Pharm Res. 1991 Jul;8(7):958-61. doi: 10.1023/a:1015832302605.
Diphtheria toxoid, which is an important vaccine in the expanded program of immunization (EPI) in the developing countries, was microencapsulated using poly(D,L,-lactide) of 49,000 molecular weight and the in-water drying technique. The microcapsules were subjected to an in vitro antigen release study using a sensitive enzyme-linked immunosorbent assay (ELISA) developed in the laboratory. Antibody titers in immunized Balb/C mice were also determined using direct ELISA. The antibody units in the immunized group till day 75 were quite comparable to those in the group receiving conventional three-dose injection of diphtheria toxoid with calcium phosphate as an adjuvant. SEM photographs of the microcapsules during in vitro degradation demonstrated the erosion kinetics of the polymer, leading to controlled release of the antigen.
白喉类毒素是发展中国家扩大免疫规划（EPI）中的一种重要疫苗，采用分子量为49000的聚（D，L-丙交酯）和水相干燥技术进行微囊化。使用实验室开发的灵敏酶联免疫吸附测定（ELISA）对微囊进行体外抗原释放研究。还使用直接ELISA测定免疫的Balb/C小鼠中的抗体滴度。直到第75天，免疫组中的抗体单位与接受以磷酸钙作为佐剂的传统三剂量白喉类毒素注射的组中的抗体单位相当。微囊在体外降解过程中的扫描电子显微镜照片显示了聚合物的侵蚀动力学，从而实现了抗原的控释。
