Optimization of Production Conditions for Extracellular Vesicles from Lacticaseibacillus Paracasei LH23 Using Response Surface Methodology: Enhancement of Yield and Exploration of Stability, Safety, and Anti-inflammatory Capacity.

Extracellular vesicles (EVs) from probiotics containing multiple bioactive ingredients play important roles in intercellular communication, immunomodulation, and tumor suppression, therefore possessing enormous potential for improving health, targeted drug delivery, and vaccine development. However, the difficulty in extraction and low yield limits the widespread application of EVs. Here, response surface methodology was employed to optimize the extraction conditions of Lacticaseibacillus paracasei LH23 EVs (LP-Evs). Temperature (45 °C), EDTA (7.5 mM), and (pH 6) were determined as the most effective extraction parameters. Compared with raw LP-Evs, the optimized EVs (LP-OEvs) showed an 8.6-fold increase in particle concentration, as well as higher lipid and protein contents. Meanwhile, LP-Evs and LP-OEvs had similar resistance to gastrointestinal digestion, could be stably stored at - 20 °C and - 80 °C for 28 days, and could inhibit LPS-induced inflammation and oxidative stress in macrophages. This study provides a reference for the industrial development of EVs.