title: The Bone Regeneration Using Bone Marrow Stromal Cells with Moderate Concentration Platelet-Rich Plasma in Femoral Segmental Defect of Rats.
abstract: BACKGROUND
  Platelet-rich plasma (PRP) can provide an assortment of growth factors, but how PRP effects bone regeneration is still unknown. The aim of the study was to explore an optimal method of using PRP and bone marrow stromal cells (BMSCs).
  
  
  METHODS
  Anin vitroexperiment was first conducted to determine an appropriate quantity of PRP. BMSCs were cultured with PRP of different concentrations to assess cell proliferation and osteogenic differentiation. Following thein vitrostudy, a rat femoral segmental defect model was used. Five collagen mixtures consisting of different concentrations of PRP and BMSCs were prepared as follows, i) BMSCs and PRP (platelet 20 x 104/µl), ii) BMSCs and PRP (platelet 100 x 104/µl), iii) BMSCs and PRP (platelet 500 x 104/µl), iv) BMSCs, and v) PRP group (platelet 100 x 104/µl), were used to fill defect. New bone formation was evaluated by soft X-ray and histologic analyses were performed at 2, 4, 6 and 8 weeks postoperatively.
  
  
  RESULTS
  The cell proliferation increased PRP concentration-dependently. Cellular alkaline phosphatase activity was higher in moderate concentration than high or low concentration group'sin vitrostudy.In vivostudy, the bone fill percentage of newly formed bone in BMSCs and PRP (platelet 100 x 104/µl) was 46.9% at 8 weeks and increased significantly compared with other groups.
  
  
  CONCLUSIONS
  BMSCs with moderate level of PRP significantly enhanced bone formation in comparison with BMSCs or PRP transplant in a rat femoral defect model.
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamakawa
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hashimoto
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Takano
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Takagi
keywords: Bone marrow stromal cell; Bone regeneration; Femoral segmental defect; Platelet-rich plasma; Rat; Surgery