effects of platelet-rich plasma & platelet-rich fibrin with and without stromal cell-derived factor-1 on repairing full-thickness cartilage defects in knees of rabbits

background: the purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (prp) and platelet-rich fibrin (prf) containing stromal cell-derived factor-1 (sdf1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. methods: we created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. the knees were randomly divided into six groups (group i: untreated control, group ii: prp, group iii: prf, group iv: gelatin+sdf1, group v: prp+sdf1, and group vi: prf+sdf1). after four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type ii, and analyzed for cartilage marker genes by real-time pcr. the data were compared using statistical methods (spss 20, kruskal-wallis test, bonferroni post hoc test and p<0.05). results: macroscopic evaluations revealed that international cartilage repair society (icrs) scores of the prf+sdf1 group were higher than other groups. microscopic analysis showed that the icrs score of the prp group was significantly lower than other groups. immunofluorescent staining for collagen ii demonstrated a remarkable distribution of type ii collagen in the gel+sdf1, prp+sdf1 and prf+sdf1 groups compared with other groups. real-time pcr analysis revealed that mrna expression of sox9 and aggrecan were significantly greater in the prf+sdf1, prp+sdf1, gel+sdf1 and prf groups than the control group (p<0.05). conclusion: our results indicate that implantation of prf scaffold containing sdf1 led to the greatest evaluation scores of full-thickness lesions in rabbits.