Figure 7: In vivo angiogenic effect of the HI hydrogels.

Histological sections of hydrogels 1, 3 and 5 days after injection stained with (a) α-SMA and (b) CD31. Right panel represents high-magnification images of the boxed regions. Quantification of blood vessels number (c) and diameter (d) surrounding and penetrating into the hydrogels. M, Muscle; H, hydrogels. Results in c,d are shown as the average values±s.d. Significance levels were set at: *P<0.05, **P<0.01 and ***P<0.001. Scale bars, 100 μm.