Fig. 1

Gross appearance and histological examination of injured quadriceps muscles after transplantation of chondroitin sulfate-based HA hydrogel (HA-CS) compared to autograft treatment (AT) and no treatment groups (NT) (a-h). Macroscopic data indicate the volume of injury site is at the maximum size in NT mice compared to HA-CS and AT groups after 7 and 28 days post-transplantation (a-g; Scale bar: 2 mm). H & E staining confirmed the presence of a low number of newly generated fibers in NT as compared to AT and HA-CS groups (black arrows) after 7 days (a-d: Scale bar: 100 µm). Despite the reduction of defect size in all groups after 28 days, gross view revealed the prominent injured site in NT related to AT and HA-CS groups (e–g: Scale bar: 2 mm). The number of fibers reached maximum levels in HA-CS groups compared to NT mice. These values did not yield statistically significant differences between NT and AT groups (h; Scale bar: 100 µm). One-way ANOVA analysis with Tukey test; *p < 0.05. Adapted from [218]. (2021; Bioactive Materials; https://doi.org/10.1016/j.bioactmat.2020.10.012)