FIGURE 4.

Effect of hADSC-derived exosomes on ischemic human myoblasts as analyzed by both MTS and LDH assays. For the exposure experiments (A,B), hADSC-derived exosomes were collected and held in different combinations of trehalose and PVP40 at 4°C temperature for 1 h. Thereafter, trehalose and PVP40 were removed from the exosome solution by diafiltration using the TFF system with 1XPBS. Subsequently, ischemic human myoblasts were distributed to the different exposure groups and treated with the same exosome concentration (50 μg/mL) beside the media -treated group which treated with phenol red free media sublimated with 1% FBS for 24 h. For the freeze-drying experiments (C,D), hADSC-derived exosomes were lyophilized in each freeze-drying solution, and then stored at ambient temperature until experimental testing. Upon rehydration and removal of trehalose and PVP40, ischemic human myoblasts treated with a 50 μg/mL concentration of the lyophilized exosomes as well as the media treated group for 24 h to determine their effects on cell proliferation and reversal of cell toxicity by MTS (A,C) and LDH (B,D) assays, respectively. Data are expressed as mean ± SD (n = 6). *p < 0.01, **p < 0.0056, ***p = 0.0001, ****p < 0.0001.