Ex vivo digestion of B-mEVs, H-mEVs, and liposomes

Ex vivo digestion of B-mEVs, H-mEVs, and liposomes

The digestive juices, including saliva, gastric juice, pancreatic juice, and bile juice, were prepared as previously described (table S1, see the detail concentrations of all the components in digestion juices in Table 1 below). Briefly, to examine whether mEVs survive the gastrointestinal conditions in an ex vivo model system, 100 μl of B-mEVs, H-mEVs, or liposomes (as a control nanoparticle) was mixed with 150 μl of salivary juice in tubes and incubated at 37°C for 5 min, followed by incubation with 300 μl of gastric juice at 37°C for 120 min. Then, 300 μl of pancreatic juice and 150 μl of bile juice were added and incubated at 37°C for 60 min. PBS (replacing the digestive juices) was used as a negative control for samples to go through the same ex vivo digestion steps. All incubation was performed at 37℃ on a rotating wheel. Last, digestive juices were removed by centrifugation at 8000g at 20°C, and particle concentrations of mEVs and liposomes were determined by NTA. All chemicals and enzymes for the ex vivo model system were purchased from Sigma-Aldrich (St. Louis, MO, USA).

Table 1. Preparation of the different digestion juices.