Introduction: Skeletal muscle injuries are common in athletes, however, no effective treatment is available. Platelet rich plasma (PRP) and mesenchymal stem cells (MSCs) have been used in treatment of different musculoskeletal disorders. However, a hot debate has been raised regarding the deleterious effect of PRP injection following muscle injury.
Aim of the Work: To compare the therapeutic effect of PRP versus bone marrow derived-MSCs in the treatment of acute injury in rats' skeletal muscle.
Materials and Methods: 52 adult rats were utilized for the whole study, 32 rats as experimental groups, 10 rats for PRP production, and 10 rats for MSCs isolation. MSCs were characterized morphologically and by flow cytometer. The 32 rats were divided into: group I (control), the other 3 groups underwent induced quadriceps femoris muscle injuries without further treatment in group II (untreated injured) or followed 2 hours later on by a single intramuscular injection of either PRP in group ΙΙI or BM-MSCs in group IV respectively. After 21 days, the rats were sacrificed. The muscles were obtained for biochemical and histological investigations. Tissue homogenates were used to measure the levels of myoblast determination protein 1 (MyoD), skeletal troponin I (sTnI), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione reductase (GSH) and total antioxidant capacity (TAC). Muscle specimens were processed and examined by light and electron microscopies. Masson's trichrome-stained sections were subjected to morphometric analysis. Statistical analyses were done.
Results: Induced muscle injuries resulted in damage to the myofibers, vacuolation, cellular infiltration, damaged sarcolemma, abnormal nuclei, pleomorphic mitochondria, distorted triads, a significant increase in collagen deposition, sTnI, and MDA together with reduction in MyoD and antioxidant enzymes. The PRP-treated group showed a mixture of muscle damage and regeneration. Meanwhile, MSCs revealed better regeneration apart from a few degenerative foci.
Conclusion: BM-MSCs injection showed superb muscle regeneration with less fibrosis compared to PRP.