[Effects of implanted myoblasts with soluble carriers on severely-cryodamaged tibialis anterior muscles]

To investigate whether the implanted myoblasts with the soluble carriers can improve the repairing efficiency for the severely-cryodamaged tibialis anterior muscles.

The skeletal myoblasts were isolated from the newborn SD rats by the use of the enzyme digestion. They were purified and serially subcultivated; the subcultivated myoblasts of the 3rd generation were marked with BrdU. The severely-cryodamaged tibialis anterior muscle models were established from 84 SD rats aged 5 months. They were randomly divided into 4 groups, including Group A1 (the implanted myoblasts with the carriers-F12 containing 0.1% sodium hyaluronate), Group A2 (the implanted myoblasts, with the carriers-F12 that did not contain 0.1% sodium hyaluronate), Group B1 (the implanted carrier solution containing 0.1% sodium hyaluronate, but with no myoblasts), and Group B2 (with no carrier solution or myoblasts). Six rats were killed at the following time points: at 2, 5 and 9 days, and 2, 4, 8 and 12 weeks after operation; the immunohistochemical and the Mallory staining studies were performed for an evaluation on the repairing efficiency for the severely-cryodamaged tibialis anterior muscles. By the imaging analysis, the number of the survived cells in each group was compared at 2 days, and the area ratio of the collagen fiber in each group was also compared at 8 weeks.

The BrdU immunohistochemical staining showed that the number of the remaining implanted cells was significantly greater in Groups A1 than in Group A2, the migrating area of the myoblasts was greater, the distribution of the cells was more uniform, the cell differentiating potential was undestroyed, the repairing efficiency for the severely-cryodamaged tibialis anterior muscles was significantly improved. There was no blue-stained nucleus at each time point in Group B. The Mallory staining showed that the fibrous degeneration in the tissue repairing process was significantly inhibited in Groups A1, A2 and B1; the inhibition was most obvious in Group A1, and next in Group A2. The imaging analysis indicated that at 2 days after operation, the number of the survived cells was significantly greater in Group A1 than in Group A2 (P<0.05). At 8 weeks after operation, the collagen fiber was the least in Group A1, less in Group A2, more in Group B1, and the most in Group B2 (P<0.05).

The implanted myoblasts can significantly improve the repairing efficiency for the severely-cryodamaged muscle tissues, and the implanted carrier solution containing 0.1% sodium hyaluronate can improve the implanting efficiency for the myoblasts.