Effects of storage on pDNA protected in eEVs. The introduced pDNA into eEVs were evaluated after storage at both 4 °C or −80 °C for indicated duration. Effects of storage on pDNA copy numbers per 1 µL of EVs are shown, (A) PBS and EVB, (B) Media, and (C) Comparison of encapsulated pDNA in each storage condition. The data of PBS Day 0 were used as the data of media day 0. (n = 7). One-way ANOVA was used to evaluate the effect of the time course in the group, and unpaired t-test was used to compare different storage conditions. In all figures, significance is expressed as follows: * p ≤ 0.05 and ** p ≤ 0.01, if not otherwise specified.