title: Tissue-engineered bone constructed in a bioreactor for repairing critical-sized bone defects in sheep.
abstract: OBJECTIVE
  Repair of bone defects, particularly critical-sized bone defects, is a considerable challenge in orthopaedics. Tissue-engineered bones provide an effective approach. However, previous studies mainly focused on the repair of bone defects in small animals. For better clinical application, repairing critical-sized bone defects in large animals must be studied. This study investigated the effect of a tissue-engineered bone for repairing critical-sized bone defect in sheep.
  
  
  METHODS
  A tissue-engineered bone was constructed by culturing bone marrow mesenchymal-stem-cell-derived osteoblast cells seeded in a porous β-tricalcium phosphate ceramic (β-TCP) scaffold in a perfusion bioreactor. A critical-sized bone defect in sheep was repaired with the tissue-engineered bone. At the eighth and 16th week after the implantation of the tissue-engineered bone, X-ray examination and histological analysis were performed to evaluate the defect. The bone defect with only the β-TCP scaffold served as the control.
  
  
  RESULTS
  X-ray showed that the bone defect was successfully repaired 16 weeks after implantation of the tissue-engineered bone; histological sections showed that a sufficient volume of new bones formed in β-TCP 16 weeks after implantation. Eight and 16 weeks after implantation, the volume of new bones that formed in the tissue-engineered bone group was more than that in the β-TCP scaffold group (P < 0.05).
  
  
  CONCLUSIONS
  Tissue-engineered bone improved osteogenesis in vivo and enhanced the ability to repair critical-sized bone defects in large animals.
authors.affiliation: Department of Orthopedics, Qilu Hospital of Shandong University, No. 107 Wenhuaxi Road, Jinan, Shandong, 250012, China, deqianglicn@163.com.
authors.forename: Deqiang
authors.initials: D
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Peilai
authors.initials: P
authors.lastname: Liu
authors.forename: Yuankai
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianxi
authors.initials: J
authors.lastname: Lu
authors.forename: Jianmin
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D019149:Bioreactors; D001842:Bone and Bones; D002130:Calcium Phosphates; D002516:Ceramics; D059630:Mesenchymal Stem Cells / Q000737:chemistry; D010012:Osteogenesis; D012756:Sheep; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014945:Wound Healing / Q000502:physiology
chemical_list: D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate