(A) The recovery rate was calculated after 24 and 72 h of incubation. (B) The viability of the islets was assessed using calcein-AM and PI. Viable cells were stained green and dead cells were stained red. Almost all MSCs and MSC sheets were viable. (C) Viability of the islets cultured alone and cocultured with MSCs and MSC sheets. (D) The insulin levels changed along with the change in the glucose concentration. The SI was calculated in the cultured-alone group and cocultured with MSCs and MSC sheet groups. (E–G) The secretions of VEGF, HGF, and TGFβ1 in the supernatants obtained from the islets alone, islets cocultured with MSCs, and MSC sheet groups. n=5 each. *p<0.05, **p<0.01 compared to the group of islets cultured alone. HGF, hepatocyte growth factor; PI, propidium iodide; SI, stimulation index; TGFβ1, transforming growth factor beta 1; VEGF, vascular endothelial growth factor.