Effects of gastrointestinal digestion on the cell bioavailability of sodium alginate coated liposomes containing DPP-IV inhibition active collagen peptides

Delivery matrices in foods need to be carefully designed for optimal delivery and to ensure that beneficial compounds are subsequently absorbed in the gut. It has been found that polysaccharide coating improved the cellular uptake of liposomes, but there is a lack of research on the effect of digestion on the cellular uptake of polysaccharide-coated liposomes. Herein, the sodium alginate-coated liposomes were prepared, combination of Caco-2, HT29 and Caco-2/HT29 cell models were used to assess the effect of digestion behavior on the bioavailability. Where, the bioavailability of digested liposomes was 1.60 times higher than that of undigested liposomes. Specifically, digestion firstly improved the ability of liposomes to penetrate the mucus layer by 1.43-fold. Secondly, digestion improved the uptake of liposomes into the intestinal cells by about 1.33-fold. Next, cellular uptake mechanisms were explored using uptake inhibition experiments. Proteomics and metabolic process experiments showed that liposomes pass intact through the small intestinal epithelium into the somatic circulation. This work suggested that digestive behavior enhanced liposome bioavailability in terms of penetration through the cellular mucus layer as well as uptake capacity. These results deepen the understanding of the specific role of digestion on polysaccharide-modified liposomes and favor a better design of delivery systems.