Optimization of angelica sinensis polysaccharide-loaded Poly (lactic-co-glycolicacid) nanoparticles by RSM and its immunological activity in vitro

In this study, angelica sinensis polysaccharide (ASP) was encapsulated into the Poly (lactic-co-glycolicacid) (PLGA) to constitute the ASP-PLGA. The aim of the study is to obtain optimal encapsulation efficiency of ASP-PLGA by optimizing the preparation conditions and investigate the immunological enhancement activity of ASP-PLGA. To obtain the optimal processing parameters, the parameters, such as the ratio of organic phase (o) to internal water phase (w1), the ratio of external water phase (w2) to organic phase (o) and the concentration of Pluronic F68 (F68) (w/v) were examined through response surface methodology (RSM). The optimum preparation conditions of ASP-PLGA for maximizing encapsulation efficiency (EE) was as follows:ratio of organic phase (o) to internal water phase (w1) at 10:1, ratio of external water phase (w2) to organic phase (o) at 11:1, the concentration of F68 at 0.8% and the experimental EE 67.89 ± 0.48% was achieved. In addition, the results showed that ASP-PLGA could significantly promote the lymphocytes proliferation and increase the ratio of CD4+ to CD8+ T cells compared with ASP and blank PLGA. This study provided strong evidence that the immunological enhancement of ASP was significantly improved through establishing a drug delivery system with PLGA.