Immunoregulatory effects on RAW264.7 cells and subacute oral toxicity of ultra-large pore mesoporous silica nanoparticles loading Lycium barbarum polysaccharides

Abstract

As a drug delivery carrier, ultra-large pore mesoporous silica nanoparticles (UCMS) are more flexible and sturdier than traditional drug delivery systems, which enable protect drugs and proteins from the destruction of gastrointestinal acid environment and enzymes. The purpose of this study was to develop ultra-large pore mesoporous silica nanoparticles loading Lycium barbarum polysaccharides (LBP-UCMS) as a novel and safe immunopotentiator, thence immune effect on macrophages and subacute oral toxicity of LBP-UCMS were investigated. UCMS were prepared successfully through a silica sol-gel reaction, followed by physical agitation to obtain LBP-UCMS. Various techniques were used to characterize the structure and morphology of LBP-UCMS, resulting in the successful loading of LBP into UCMS. As innate immune cells, macrophages play an important role. In vitro study demonstrated the immune-enhancing activity of LBP-UCMS on RAW264.7, including enhancement phagocytosis of macrophages, up-regulation the expression of costimulatory molecules CD80, CD86 and MHCII, and stimulation the production of cytokines (TNF-α, IL-1β and IL-6). For the evaluation of LBP-UCMS safety, mice were administered LBP-UCMS for 14 consecutive days. The results of in vivo study showed that oral administration of LBP-UCMS (200, 400 and 800 mg/kg) for 14 days was safe. Hence, UCMS is an effective and safety platform for delivery of LBP for improving the effect of its clinical application.