Effect of Allogenic Mesenchymal Stem Cell Injection on Functional Repair Outcomes Following Skeletal Muscle Laceration Injury.

Background

Skeletal muscle laceration injuries remain a clinical challenge owing to limited and often delayed functional recovery. Surgical repair often fails to fully restore injured muscle, causing fibrosis and functional impairments. Mesenchymal stem cells (MSCs) represent a potential therapy due to their regenerative and immunomodulatory properties. However, their short-term regenerative effects in laceration injuries remain under-explored.

Objective

We aim to evaluate the short-term effects of allogenic bone marrow-derived MSCs on skeletal muscle regeneration following laceration injury in rats.

Methods

Sprague Dawley rats underwent laceration injury to the right gastrocnemius muscle and received local injection of either saline (n = 6) or allogeneic bone marrow-derived MSCs (2 × 106 cells; n = 6) two weeks after injury. Muscle functional recovery was evaluated by measuring tetanic contraction force of the injured relative to the contralateral uninjured leg and compared among MSC-treated, saline-treated, untreated injured (n = 6), and intact control groups (n = 6) on days 7 and 14 post-treatment. Histological assessment of the treated muscle groups using Hematoxylin and Eosin and Masson's Trichrome staining was conducted on day 7 post-treatment.

Results

On day 7 post-treatment, MSC-treated muscle showed higher normalised force (96.8 ± 15.0%) than saline-treated (76.7 ± 4.6%) (p = 0.0393), but not untreated, muscle (83.1 ± 14.7%) (p = 0.2259). By day 14, the MSC-treated group exhibited significantly greater recovery of muscle force (110.8 ± 6.46%) than both the saline-treated (78.4 ± 6.47%) (p < 0.0001) and untreated groups (88.1 ± 3.41%) (p = 0.0001). Force recovery in the MSC-treated muscle was comparable to that in intact muscle (102.6 ± 10.4%) at both time points (p = 0.230). Supplementary histological analysis showed mild inflammatory cell infiltration, well-formed myoblasts, and a lower fibrosis index in MSC-treated muscle (29.30 ± 0.29%) compared with saline-treated muscle (31.77 ± 0.43%) (p < 0.0001) on day 7 post-treatment.

Conclusions

Allogeneic bone marrow-derived MSC therapy is associated with enhanced repair of lacerated skeletal muscle over a short recovery period; however, larger studies with broader assessments are needed to confirm its potential clinical applicability.