The effect of platelet-rich plasma on canine bone marrow stromal cells in the micro-environment of femoral head necrosis

Objective To observe the effect of platelet-rich plasma (PRP) on the proliferative and osteogenetic activity of canine bone marrow stromal cells (BMSCs) in the micro-environment of femoral head necrosis (FHN).Methods The FHN microenvironment was simulated with Dulbecco's modified Eagle medium (DMEM) containing 5％ volume FHN soak solution.Whole bone marrow culture was used to culture BMSCs from an adult mongrel.The 3rd BMSCs were divided into 5 even groups:blank group (added with normal DMEM),group A (added with DMEM with 5％ soak solution),group B (added with DMEM with 5％ soak solution and 5％ PRP),group C (added with DMEM with 5％ soak solution and 10％ PRP) and group D (added with DMEM with 5％ soak solution and 15％ PRP).The proliferation of BMSCs in each group (n =6) was examined by the MTT assay at 3,6 and 8 days.Furthermore,extracellular alkaline phosphatase (ALP) assay (at 7 days),ALP staining (at 10 days) and the calcium staining (at 19 days) were used to evaluate the osteogenic differentiation of BMSCs.Results At 3,6 and 8 days,the optical density (OD) was significantly larger in group A than in the blank group (P ＜ 0.05),and significantly larger in groups B,C and D than in group A (P ＜ 0.05).The OD was significantly larger in group D than in groups B and C at 6 days (P ＜ 0.05).At 8 days,group D showed the largest OD,followed by group C and last by group D,with significant differences between groups (P ＜ 0.05).Extracellular ALP assay,ALP staining and calcium staining showed that the osteogenic differentiation in group B was significantly stronger than in the other groups (P ＜ 0.05) but there were no significant differences between the other 4 groups (P ＞ 0.05).Conclusions In the FHN micro-environment,PRP promotes proliferation of canine BMSCs and low density PRP accelerates osteogenic differentiation of canine BMSCs. Key words: Platelet-rich plasma;  Femur head necrosis;  Mesenchymal stem cells;  Cell proliferation;  Cell differentiation