Isolation of a new population of lacticaseibacillus casei bl23 extracellular vesicles by hydrostatic filtration?

D´ANTONI CL; CHIAPETTA, DIEGO A.; MORETTON MA.; PEREZ OE; DOMINGUEZ RUBIO AP; PIURI M

Mar del Plata

Otro; Reunión Conjunta SAIC-SAI-SAFIS 2022; 2022

Probiotic-derived extracellular vesicles (EVs) are naturally produced delivery systems with potential therapeutic purposes. The traditional method to isolate EVs is ultracentrifugation (UC). However, this method has many disadvantages, like EV lysis and high rates of contamination with bacterial proteins. The aim of this work was to compare the alternative method hydrostatic filtration (HF) for the isolation of EVs released by Lacticaseibacillus casei BL23 with the UC traditional method. In this work we reported for the first time the presence of two discernible populations of L. casei BL23-derived EVs as revealed by DLS and TEM. The size distribution for HF samples showed abimodal distribution (peaks: 15 nm, 94 nm) unlike the pellet obtained by UC, in which a single size population was observed (peak: 59 nm). The pellet obtained by UC after HF (HF+UC pellet)showed a single size population (peak: 63 nm) and the UC supernatant after HF (HF+UC SN) showed a bimodal distribution (peaks: 16 nm, 197 nm), confirming the recovery of larger EVs inthe HF sample and revealing the remaining of both EV populations in the supernatant, respectively. By TEM the presence of the larger size EV population was confirmed, and there were nanoparticleswith a diameter below 30 nm. These results must be confirmed by other EV characterization methods, such as NTA (Nanoparticle Tracking Analysis) and AFM (Atomic Force Microscopy).