Optimization of Glycyrrhiza polysaccharide liposome by response surface methodology and its immune activities

Glycyrrhiza polysaccharide liposome (GPSL) was prepared by reverse-phase evaporation method and optimized with response surface methodology. As a result, the optimum preparation conditions were as follows: the ratio of soybean phosphatide to Glycyrrhiza polysaccharide (GPS) of 24:1, temperature of drug incubation of 46 °C, the ultrasound time of 16 min. Confirmation experiments and transmission electron micrograph (SEM) exhibited the entrapment efficiency of liposome as 78.33 ± 0.25%, with spherical shape and uniform sizes. Furthermore, proliferation assay, allogeneic mixed lymphocyte reaction and supernatant cytokines of chBM-DCs were performed by MTT and ELISA methods to investigate the immune-modulating effects of GPSL and GPS. The results showed that GPSL could significantly promote the proliferation of immature chBM-DCs, enhance the ability of mature chBM-DCs to induce T-cell proliferation and modulate the mature chBM-DCs to secret cytokines such as IL-2, IFN-γ and IL-10. These evidences indicated that the immune-modulating activity of GPS was significantly improved after encapsulated with liposome.