FIGURE 5.

Bright‐field and viability images (at day 7) of monospheroids (0–1 = MSC only; 1–0 = β‐cell only) and heterospheroids INS‐1 (upper row), MIN6 (middle row), and 1.1B4 (lower row) cocultured with hMSC‐TERTs at different cell ratios. The stated viabilities of the spheroids were assessed by measuring the red (core) and green (whole spheroid) diameter and the resulting volume to describe the real “3D viability,” but the displayed images only represent two dimensions of the spheroids, which could provide a deceptive impression. Scale bar = 100 μm. 1.1B4, a cell line formed by the electrofusion of primary human pancreatic islets and PANC‐1 cells; hMSC‐TERT, human mesenchymal stromal/stem cells immortalized with reverse transcriptase telomerase; INS‐1, rat insulinoma‐1 cell line; MIN6, mouse insulinoma‐6 cell line; MSC, mesenchymal stromal/stem cell