Intervertebral disc regeneration using platelet-rich plasma-containing bone marrow-derived mesenchymal stem cells: A preliminary investigation

Platelet-rich plasma (PRP) is a promising strategy for intervertebral disc degeneration (IDD). However, the short half-life of growth factors released from PRP cannot continuously stimulate the degenerated discs. Thus, the present study hypothesized that the combined use of PRP and bone marrow-derived mesenchymal stem cells (BMSCs) may repair the early degenerated discs in the long term for their synergistic reparative effect. In the present study, following the induction of early IDD by annular puncture in rabbits, PRP was prepared and mixed with BMSCs (PRP-BMSC group) for injection into the early degenerated discs. As controls, phosphate-buffered saline (PBS; PBS group) and PRP (PRP group) were similarly injected. Rabbits without any intervention served as a control group. At 8 weeks following treatment, histological changes of the injected discs were assessed. Magnetic resonance imaging (MRI) was used to detect the T2-weighted signal intensity of the targeted discs at weeks 1, 2 and 8 following treatment. Annular puncture resulted in disc narrowing and decreased T2-weighted signal intensity. At weeks 1 and 3, MRI examinations showed regenerative changes in the PRP-BMSC group and PRP group, whereas the PBS group exhibited a continuous degenerative process of the discs. At 8 weeks post-injection, the PRP-BMSCs induced a statistically significant restoration of discs, as shown by MRI (PRP-BMSCs, vs. PRP and PBS; P<0.05), which was also confirmed by histological evaluations. Thus, compared with PRP, the administration of PRP-containing BMSCs resulted in a superior regenerative effect on the early degenerated discs, which may be a promising therapeutic strategy for the restoration of early degenerated discs.