Fig. 4

Photomicrograph of initial linear defect (scratch) created with a 200 μl pipette tip compared with same scratch at time 36 h post scratch and at end of study (72 h) for each experimental group. Magnification 4×, scale bar = 500 μm. a–c Photomicrographs of the same horse from the control group at time 0, 36 h, and 72 h, respectively. d–f Photomicrographs of the same horse from the MSC-Sp group at time 0, 36 h, and 72 h, respectively. g–i Photomicrographs of the same horse from the BM-MSC group at time 0, 36 h, and 72 h, respectively