Oral Administration Properties Evaluation of Three Milk-derived Extracellular Vesicles Based on Ultracentrifugation Extraction Methods.

Milk-derived extracellular vesicles (M-EVs) are low-cost, can be prepared in large quantities, and can cross the gastrointestinal barrier for oral administration. However, the composition of milk is complex, and M-EVs obtained by different extraction methods may affect their oral delivery. Based on this, we propose a new method for extracting M-EVs based on cryogenic freezing treatment (Cryo-M-EVs) and compare this method with the previously reported acetic acid treatment (Acid-M-EVs) method and the conventional ultracentrifugation method (Ulltr-M-EVs). The new method simplifies the pretreatment step and achieves 25-fold and 2-fold higher yields than Acid-M-EVs and Ulltr-M-EVs. And it was interesting to note that Cryo-M-EVs and Acid-M-EVs had higher cellular uptake efficiency, and Cryo-M-EVs presented the best transepithelial transport effect. After oral administration of the three M-EVs extracted by three methods in mice, Cryo-M-EVs effectively successfully crossed the gastrointestinal barrier and achieved hepatic accumulation, whereas Acid-M-EVs and Ultr-M-EVs mostly resided in the intestine. The M-EVs obtained by the three extraction methods showed a favorable safety profile at the cellular as well as animal level. Therefore, when M-EVs obtained by different extraction methods are used for oral drug delivery, we can utilize their accumulation properties at different sites to better deal with different diseases. This article is protected by copyright. All rights reserved.