| Selenium nanoparticles(SeNPs)products have a very important position and application prospects in the fields of functional food and medicine.Unlike ordinary elemental selenium,SeNPs have a significant scavenging effect on free radicals,can enhance the body’s immunity,and have the characteristic of low toxicity.At present,SeNPs are mainly prepared using physical and chemical methods,but they have the disadvantages of poor stability and easy aggregation,which is not conducive to human absorption and utilization.By using Lycium barbarum polysaccharide protein complex as a stabilizer,not only can the stability of SeNPs be improved,but also synergistic effects in biological activity can be exerted.Based on this,this project first uses subcritical water to prepare bartarum polysaccharide-protein complexes,and then uses these complexes to stabilize SeNPs and characterize their structure.Finally,the digestion and absorption characteristics and in vitro anti-proliferation ability of Lycium barbarum polysaccharide-protein complexes to stabilize SeNPs are explored.The main research contents and results are as follows:(1)Preparation and structural characterization of Lycium barbarum polysaccharidesprotein complex stabilized SeNPs.Using Lycium barbarum as raw materials,Lycium barbarum polysaccharides and Lycium barbarumproteins were obtained by water bath stirring extraction combined with three-phase separation method.The effects of single factor conditions(ammonium sulfate addition,nbutanol addition,reaction temperature,reaction pH)on the extraction rate of polysaccharides and proteins were investigated.Then,the Lycium barbarum polysaccharide-protein complex was prepared using subcritical water method and traditional wet heat method,and SeNPs were stabilized using this complex.The preparation conditions were optimized by adjusting the concentration of Lycium barbarum polysaccharide and protein to improve the stability of SeNPs.The results indicate that when the ratio of Se to LBPP1 is 1:3,LBPP1-SeNPs are the most stable.SEM results show that LBPP1-SeNPs have a smoother surface compared to SeNPs.After investigation of physical stability,it was found that LBPP1-SeNPs were more dispersed,with a more uniform size distribution,and their particle size remained between 111.5 and 117 nm within 40 days.(2)Digestion and absorption characteristics of Lycium barbarum polysaccharide-protein complex stabilized SeNPsPreliminary exploration of the digestive characteristics of LBPP1-SeNPs using an in vitro digestion model,and exploration of the transport and absorption mechanisms of LBPP1SeNPs using the Caco-2 monolayer cell model.The results showed that after gastrointestinal digestion,the particle size of LBPP1-SeNPs increased from 116.1 nm to 138.2 nm,while the particle size of SeNPs increased from 138.7 nm to 343.7 nm,an increase of 205 nm,and the particle size of LBPP1-SeNPs remained lower than that of SeNPs throughout the entire digestion process.The selenium release rates of LBPP1-SeNPs and SeNPs reached 4.43%and 12.85%respectively after 120 minutes of digestion.In addition,experiments on Caco-2 cell transport have shown that the uptake and transport of LBPP1-SeNPs are energy and concentration dependent,mainly mediated by endocytosis in Caco-2 cells.(3)Anti-proliferative ability effect of Lycium barbarum polysaccharides-protein complex on stabilizing SeNPs in caner cellsTo investigate the inhibitory effect of LBPP1-SeNPs on Caco-2 cells and HepG2 cells through MTT experiments,and to preliminarily explore the mechanism of inducing HepG2 cell apoptosis.The results showed that LBPP1-SeNPs had significant inhibitory effects on both Caco-2 cells and HepG2 cells,and relatively speaking,the inhibitory effect on HepG2 cells was more pronounced.In addition,LBPP1-SeNPs can induce apoptosis in HepG2 cells by inducing the activation of Caspase-3,Caspase-8,and Caspase-9 in cells. |
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