seyed hamze hosseini

This study aimed to evaluate different isolation methods, including ultracentrifugation (UC) and polyethylene glycol (PEG)-based precipitation of extracellular vesicles (EVs) from Aloe vera and investigate their yield, purity, and physicochemical properties. Plant-derived extracellular vesicles (PDEVs) have attracted increasing attention as natural nanocarriers for biomedical, nutraceutical, and food-related applications. In this study, EVs were isolated from Aloe vera leaf peel and gel using UC and PEG methods. The EVs were characterized by nanoparticle tracking analysis (NTA), NanoDrop protein quantification, and zeta potential measurements. Aloe vera gel-derived EVs using the UC method showed higher particle concentrations, more consistent size distributions, and lower protein contamination compared with peel and gel PEG-derived samples. The PEG isolation markedly increased apparent protein concentration, especially in the gel, indicating co-precipitation of non-vesicular plant components and polymer-associated artifacts. Zeta potential analysis further revealed significant surface charge variation on PEG-derived vesicles, both in peel and gel, particularly after high-speed centrifugation. In conclusion, these results demonstrate that UC provides superior purity and physicochemical stability of Aloe vera EVs, while PEG precipitation inflates protein yield and alters vesicle surface properties. The present study highlights the importance of the isolation method, which affects its potential applications.