关键词: 纳米脂质载体；脂质相组成；蜂蜡；消化释放；巨噬细胞摄取；黏液黏附渗透

Abstract: Lipid phase composition of nanostructured lipid carriers (NLCs) modulates their digestive release behavior and cellular uptake by macrophage. In this study, the effects of the percentage of beeswax in the binary lipid mixture on the physical properties, lipid digestion, curcumin release, intestinal adhesion and penetration, and macrophage uptake of NLCs were investigated by in vivo simulated digestion, ex vivo intestinal adhesion and penetration and RAW264.7 mouse macrophage uptake experiments. The results showed that the particle size, loading efficiency and encapsulation efficiency of NLCs increased with an increase in the percentage of beeswax in the lipid phase. Compared with NLCs without beeswax (NLC0), whose oil phase consisted of medium chain fatty acid triglycerides (MCT), addition of 5% or 10% beeswax to MCT significantly improved the apparent viscosity, physical stability, intestinal mucosal adhesion and penetration of NLCs (the fluorescence signal intensity of curcumin in epithelial cells increased by 20.27% and 55.02%, respectively). Additionally, with an increase in beeswax content, the lipolysis efficiency, the release rate of free fatty acid (FFA) and the amount of released curcumin from NLCs decreased significantly; the release rate of FFA decreased in the following order: KNLC0 (0.13 min-1) > KNLC5 (0.08 min-1) > KNLC10 (0.06 min-1), and the amount of released curcumin declined in the following order: RNLC0 ((99.93 ± 0.09)%) > RNLC5 ((96.38 ± 0.05)%) > RNLC10 ((90.05 ± 0.05)%), indicating sustained release characteristics. Compared with free curcumin, NLCs promoted the enrichment of curcumin in RAW264.7 macrophages by 5.68–6.25 times. These findings can provide guidance for the application of beeswax based NLCs in oral delivery of lipophilic active ingredients and regulation of health effects.

Key words: nanolipid carrier; lipid phase composition; beeswax; digestive release; macrophage uptake; mucosal adhesion and penetration