Fig. 7

Ultrasonic and histological evaluation of the gastrocnemius. a Representative results of ultrasonic elastography of the gastrocnemius at week 6 after cell transplantation are shown in the first row. The elastomeric map (left) and Young’s modulus maps (right) are shown for each group. In the photographs in the middle row, the gastrocnemius on the injured side shows visible atrophy in the hollow and uASCs groups compared with the normal side at week 12 after cell transplantation; in contrast, the other three groups were less pronounced. Representative Masson’s trichrome staining results of the gastrocnemius are shown in the bottom row. All groups showed hyperplasia of blue-stained collagen fibers distributed among muscle fibers stained in red. b Although the gastrocnemius elasticity ratio was not significantly different among sustaining dASCs 7d (57.05 ± 4.59%), intermittent dASCs (60.79 ± 4.21%), and autograft groups (64.36 ± 4.01%), these values were significantly higher (p < 0.01) than those in the hollow (43.88 ± 6.03%) and uASCs groups (45.81 ± 4.44%). c At the twelfth week after cell transplantation, the gastrocnemius wet weight ratio in intermittent dASCs (71.46 ± 2.78%) was significantly greater (p < 0.05) than those in the hollow (44.70 ± 3.51%), uASCs (49.00 ± 3.15%), and sustaining dASCs 7d groups (64.45 ± 2.91%). d The mean cross-sectional area of gastrocnemius fibers in the intermittent dASCs group (1332.24 ± 60.17 μm²) was significantly greater (p < 0.01) than those in the hollow (568.04 ± 108.59 μm²), uASCs (807.80 ± 49.20 μm²), and sustaining dASCs 7d groups (1107.81 ± 82.86 μm²) at the twelfth week after cell transplantation. Data are expressed as means ± SEM. *p < 0.05, **p < 0.01, one-way ANOVA with Tukey’s post-test or Dunnett’s T3 post-test. dASC, differentiated adipose-derived stem cell; n.s., no significant difference; uASC, undifferentiated adipose-derived stem cell