Direct Experimental Evidence for Selective Uptake of Function-Specific Small Extracellular Vesicles by Recipient Cells.

Small extracellular vesicles (sEVs), ranging from 30 to 200 nm in diameter, are a subset of extracellular vesicles that play an essential role in intercellular communication by transporting bioactive molecules between cells. Due to their diverse cargo and origins, sEVs form a highly heterogeneous population. Previous studies have suggested that recipient cells uptake specific sEVs to ensure accurate signalling, but direct experimental evidence on how cells effectively communicate in such a complex and noisy environment has been lacking. In this study, we provide direct experimental evidence by developing a method to retrieve and analyze internalized sEVs from the intracellular membrane compartments of recipient cells. Using this sEV retrieval method, we isolated sEV subpopulations from two types of breast cancer cells after incubation with sEVs derived from mixed cell cultures. We then assessed their functional roles by evaluating the phenotypic responses of cells treated with these retrieved sEV subpopulations. Our results reveal apparent differences in their functional impacts, indicating that cells employ a function-based mechanism to selectively uptake sEVs. This finding advances our understanding of how cells enhance communication efficiency via sEVs. Further investigation into this phenomenon could offer deeper insights into intercellular communication and its role in health and disease.