Selenium Myricaria germanica Polysaccharides‐based Nanoparticles to Improve Immune Activity

ABSTRACT In this study, a nano‐drug delivery system based on poly(lactic‐co‐glycolic acid) (PLGA) that modified selenated Myricaria germanica polysaccharide (sMGP) was developed to enhance immune responses. At the O to W1 ratio of 8.29, the W2 to primary emulsion ratio of 7.62, and the concentration of PLGA was 37.94 mg/mL, the entrapment efficiency of sMGP‐PLGA was 90.27%. In vitro, at the concentration of 3.125–25 µg/mL, sMGP‐PLGA significantly enhanced the phagocytosis of RAW264.7 macrophages, facilitated the upregulation of surface molecules CD40 and CD86, and increased the secretion of cytokines interferon‐gamma (IFN‐γ) and interleukin (IL)‐4, as well as the gene expression levels of toll‐like receptor 4 and nuclear factor kappa B. In vivo sMGP‐PLGA significantly increased the Newcastle disease antibodies, IFN‐γ, and IL‐6 levels, activated the immune functionality of spleen, thymus, and bursa of Fabricius, and improved the organ index. Meanwhile, sMGP‐PLGA promoted the proliferation of T and B lymphocytes. These findings indicate that sMGP‐PLGA could enhance the immune activity.