Figure 8.

Typical histological changes in normal disc (a–d), MSC and hydrogel (e–h), hydrogel (i–l), and untreated (m–p). On Safranin O stained sections, a moderate-to-severe degeneration was observed in the hydrogel (k, l) and untreated (o, p) groups with formation of fibrocyte-like cells. In the MSC containing hydrogel group, the increasing number of chondrocyte-like cells which appeared as large cells encircled with pericellular matrix densely stained with Safranin O was found in the nucleus pulposus (g, h).