PLGA微球/纳米球作为乙型肝炎表面抗原疫苗载体研究进展

Research progress on poly(lactide-co-glycolide) nano/micro-particles as HBsAg carriers

乙型肝炎（乙肝）病毒（hepatitis B virus,HBV）可引发肝炎、肝硬化、肝功能衰竭、肝癌或其他肝脏损害,是一种严重危害人类身体健康的病原微生物。据调查,中国乙型肝炎病毒表面抗原（hepatitis B virus surface antigen,HBsAg）携带者占人口的7.18%,是名符其实的肝炎大国[1]。

Currently available commercial HBsAg vaccines don′t always show sufficient vaccination effects.In this review,we summarize an excellent drug carrier,PLGA,and emphasize on the method of preparation,modification and application as an immune carrier.Preparation includes solvent evaporation,spray drying,membrane emulsification,capillary flow,and etc.The PLGA microspheres or nanoparticles could control the antigen release and more easily taken in by antigen-presenting cells because their granular structure is similar to that of viruses.PLGA leads to stronger immune reactions when absorbing cations or targeting molecules on the surface.Common materials for the surface modifications include polyethylene glycol,chitosan,lectin,polyethylene imine,protamine and so on.When incubated with mouse bone marrow-derived dendritic cells（BMDC）,the PLGA microspheres/nanoparticles can significantly promote BMDC to express peripheral proteins and secrete cytokines such as IL-12p70（promoting Th1polarization）.The PLGA microspheres/nanoparticles not only stimulate animals to produce high levels of IgG as traditional vaccine,but also promote animals to secret cytokines reflecting cellular immune such as IL-2and IFN-γ.In addition,it was found that microspheres/nanoparticles can escape from the lysosome in the process of internalization by antigen-presenting cells.In this way,it happens to achieve cross-presentation and further generate humoral and cellular immunity.