title: [Tissue engineering vascularized bone repairing segmental femoral bone defects in rabbits].
abstract: OBJECTIVE
  To investigate the effectiveness and mechanism of tissue engineering vascularized bone in repairing segmental femoral bone defects in rabbits.
  
  
  METHODS
  Thirty-two rabbits were randomized into two groups (n = 16 each). A segmental and critical bone defect of 15 mm in length was made at left femur. In experimental group, the tissue engineering bone constructed from autologous bone marrow mesenchymal stem cells plus beta-tricalcium phosphate (beta-TCP) and vascular bundle was implanted into bony defect. In control group, there was no implantation of vascular bundle. Animals were sacrificed at 2, 4, 8 and 12 weeks post-implantation respectively. Histological observation was conducted to determine the process of new bone formation and remodeling. The expression of vascular endothelial growth factor (VEGF) in new bone was measured by immunohistochemistry, real-time PCR and Western blot.
  
  
  RESULTS
  As indicated by histological observations over time, new bone formation increased in both groups. It was better in the experimental group than the control group at the beginning of 4 weeks. The expression level of VEGF gradually decreased in each group after an initial rise. And the expression of VEGF was significantly higher than the control group after implantation at all time points and peaked at 4 weeks.
  
  
  CONCLUSIONS
  Tissue engineering vascularized bone accelerates bone repair in critical size defect model of femur in rabbit. Implantation of vascular bundle can promote the secretion of VEGF. And VEGF is an essential mediator of both angiogenesis and ossification.
authors.affiliation: Department of Orthopedic Surgery, Third Affiliated Hospital, Guangzhou Medical University, Third Affiliated Hospital, Guangzhou 510150, China.
authors.forename: Le
authors.initials: L
authors.lastname: Wang
authors.forename: Guo-Xian
authors.initials: GX
authors.lastname: Pei
authors.forename: Liang-Bin
authors.initials: LB
authors.lastname: Gao
authors.forename: Shan
authors.initials: S
authors.lastname: Jiang
authors.forename: Tian-Wang
authors.initials: TW
authors.lastname: Mu
authors.forename: Si-Yuan
authors.initials: SY
authors.lastname: Chen
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Qin
authors.forename: Dan
authors.initials: D
authors.lastname: Jin
authors.forename: Ai-Ju
authors.initials: AJ
authors.lastname: Lou
authors.forename: Pei-Ran
authors.initials: PR
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D018786:Bone Substitutes; D018483:Diaphyses / Q000293:injuries; D018919:Neovascularization, Physiologic; D010012:Osteogenesis; D011817:Rabbits; D023822:Tissue Engineering / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014945:Wound Healing
chemical_list: D018786:Bone Substitutes; D042461:Vascular Endothelial Growth Factor A