Effects of Platelet-Rich Plasma on Cartilage Grafts in Rabbits as an Animal Model

BACKGROUND Cartilage tissue has limited regenerative capacity and the management of cartilage defects has always been a challenging issue. Platelet-rich plasma (PRP) has been recently been used to improve healing of cartilage defects. In the present experiment, we aimed to investigate the effects of PRP on regeneration capacity as well as survival of the cartilage grafts in a rabbit model. METHODS In 15 white New Zealand rabbits, auricular cartilage was used to produce 4 pieces of cartilage (each about 2×2 cm). Two samples were diced to small pieces and 2 samples left intact. PRP was prepared using 5 ml of auricular blood. After measuring of the weight and volume of cartilages, they mixed with either normal saline or PRP and then implanted on the back of the rabbit. After 12 weeks, the implants were removed and the weight and volume were measured and the numbers of nucleated lacunae were counted on H & E staining. RESULTS Histological findings showed that in both the intact and diced cartilages, adding PRP resulted in increasing regeneration of chondrocytes. Moreover, adding PRP to intact cartilages had a significant effect in maintaining the grafts 'weight and volume (p<0.05) but in diced cartilages, this effect was not significant. CONCLUSION Our findings yielded valuable information on the effect of PRP on survival and regeneration of autologous cartilage grafts as the extent of angiogenesis and the diameters of vessels were more pronounced in the side using PRP and markedly lesser reduction of weight and volume were visible in this group. PRP was effective in increasing survival and regeneration capacity of cartilage grafts in rabbit model.