Western Blot analysis
All of the following antibodies were purchased from ThremoFisher Scientific, USA; MFGE8 (Lactadherin) Monoclonal Antibody (EDM45), MFGE8 (Lactadherin) Polyclonal Antibody, and CD63 goat polyclonal antibody and used for Western Blot analyses. Samples containing EV pellets were suspend in PBS and diluted with lysis buffer, then were further mixed with 6x SDS sample buffer and placed at 95°C for 5 min. Gel (12% Mini-PROTEAN TGX Stain-Free, Bio-Rad, USA) run 20-25 minute at 90 V for stacking, then 1-1.5 hour at 110 V for separating. The proteins were transferred using Transfer-Blot Turbo Transfer System with Transfer pack (Bio-Rad). The membranes were blocked with 5% non-fat dried milk dissolved in TBST. The proteins were detected by incubation with secondary antibody conjugated with HRP (anti-rabbit IgG goat antibody, anti-rabbit IgG donkey antibody, and anti-goat IgG donkey antibody all by Invitrogen, USA). The membranes were washed thrice prior to imaging. Detected the peroxidase activity using a Clarity TMWestern ECL substrate (Bio-Rad) and visualized using an ChemiDocTM Imaging system (Bio-Rad).