Fig. 2
Effect of Different Molecular Weights of Hyaluronic Acid on MSC EV Uptake by Human Monocytes. a Effect of pre-incubation of MSC EV with different doses of HMW HA (1.0 MDa) on its uptake by LPS stimulated human monocytes. Compared with MSC EV alone, MSC EV pre-incubated with HA doses of 0.2, 1, or 5 μg/ml HMW HA (1.0 MDa) showed increased uptake by LPS stimulated human monocytes. There were no significant differences between the three doses of HMW HA. Data are mean ± SD for each condition, ****P < 0.0001 by ANOVA (Bonferroni), N = 9–18. Bar = 1 mM. b Effect of MSC EV pre-incubated with different molecular weights of HA on MSC EV uptake by LPS stimulated monocytes. LMW HA (40 KDa) primed MSC EV, HMW HA (1.0 MDa) primed MSC EV, and HMW HA (1.5 MDa) primed MSC EV all showed increased uptake by LPS stimulated monocytes when compared with MSC EV alone. HMW HA (1.0 MDa) primed MSC EV demonstrated the highest uptake by the monocytes. Data are mean ± SD, ****P < 0.0001 by ANOVA (Bonferroni), N = 9. Bar = 1 mM. c HMW HA (1.0 MDa) primed MSC EV significantly decreased the secretion of TNFα by LPS stimulated human monocytes when compared with MSC EV alone. Data are mean ± SD, **P < 0.01, ****P < 0.0001 by ANOVA (Bonferroni), N = 16. Dose of MSC EV (50 μl) used = 1.1 × 1010 particles