Zetaview basic nta

Nanoparticle tracking analysis (NTA) was performed using ZetaView® Basic-NTA (Particle Metrix, Germany). Pelleted EVs were resuspended in particle-free PBS and analyzed in measurement mode “Size Distribution”, 2 Cycles, 11 Positions. Germination medium and particle-free PBS were used as blank for the treatment and the control group respectively, and the measurements were performed in triplicate for each group. Eventually, particle concentrations of the blank controls were subtracted from the particle concentrations of the samples.

The quantification and purity of MVs isolated from conditioned medium were measured using the ZetaView BASIC NTA (Particle Metrix) at Cancer Research Center, University of Science and Technology of China.

hMSCs or hAAT-MSCs at 70–80% of confluence were cultured in StemPro™ MSC SFM (Thermo Fisher, Waltham, MA, USA). Cell culture medium was collected 48 h later, centrifuged at 300× g for 4 min, and then at 2000× g for 10 min. Supernatant was collected and frozen at −80 °C for further use. Exosomes were harvested using ultracentrifugation at 10,000× g for 40 min at 4 °C. The collected supernatants were centrifuged again at 100,000× g for 90 min at 4 °C. The pellets were washed with PBS and then stored at −80 °C. The size distribution of exosomes was measured by ZetaView^® BASIC NTA (Particle Metrix, Mebane, NC, USA).