Platelet-rich plasma (PRP) stimulates the extracellular matrix metabolism of porcine nucleus pulposus and anulus fibrosus cells cultured in alginate beads

Study Design. In vitro assessment of the effects of platelet-rich plasma on the extracellular matrix metabolism of porcine intervertebral disc cells. Objectives. To determine whether platelet-rich plasma is effective in stimulating cell proliferation and extracellular matrix metabolism by porcine disc cells cultured in alginate beads. Summary of Background Data. Platelet-rich plasma is used to accelerate wound healing and tissue regeneration. Activated platelets release multiple growth factors that regulate cell proliferation, differentiation, and morphogenesis. Individual growth factors present in platelet-rich plasma have been demonstrated to affect the metabolism of intervertebral disc cells. Methods. Platelet-poor and platelet-rich plasma was isolated from fresh porcine blood using a commercially available platelet concentration system. After preculture for 7 days and serum starvation for 24 hours, the beads containing nucleus pulposus and anulus fibrosus cells were then cultured for another 72 hours in serum-free medium, 10% fetal bovine serum, 10% platelet-poor plasma, or 10% platelet-rich plasma. The synthesis of proteoglycans and collagen, the accumulation of proteoglycans, and the DNA content were biochemically assessed. Results. Platelet-rich plasma had a mild stimulatory effect on cell proliferation of intervertebral disc cells. Platelet-rich plasma treatment significantly upregulated proteoglycan and collagen synthesis and proteoglycan accumulation when compared with platelet-poor plasma. Conclusions. Platelet-rich plasma was effective in stimulating cell proliferation and extracellular matrix metabolism. The response to platelet-rich plasma was greater in the case of anulus fibrosus cells than of nucleus pulposus cells. The local administration of platelet-rich plasma might stimulate intervertebral disc repair. In addition, given the risks of using animal serum for tissue engineering, autologous blood may gain favor as a source of growth factors and serum supplements needed for stimulating cells to engineer intervertebral disc tissues.