title: Tissue-engineered calcium phosphate cement in rabbit femoral condylar bone defects.
abstract: BACKGROUND
  Calcium phosphate cement (CPC) is a favorable bone-graft substitute, with excellent biocompatibility and osteoconductivity. However, its reduced osteoinductive ability may limit the utility of CPC. To increase its osteoinductive potential, this study aimed to prepare tissue-engineered CPC and evaluate its use in the repair of bone defects. The fate of transplanted seed cells in vivo was observed at the same time.
  
  
  METHODS
  Tissue-engineered CPC was prepared by seeding CPC with encapsulated bone mesenchymal stem cells (BMSCs) expressing recombinant human bone morphogenetic protein-2 (rhBMP-2) and green fluorescent protein (GFP). Tissue-engineered CPC and pure CPC were implanted into rabbit femoral condyle bone defects respectively. Twelve weeks later, radiographs, morphological observations, histomorphometrical evaluations, and in vivo tracing were performed.
  
  
  RESULTS
  The radiographs revealed better absorption and faster new bone formation for tissue-engineered CPC than pure CPC. Morphological and histomorphometrical evaluations indicated that tissue-engineered CPC separated into numerous small blocks, with active absorption and reconstruction noted, whereas the residual CPC area was larger in the group treated with pure CPC. In the tissue-engineered CPC group, in vivo tracing revealed numerous cells expressing both GFP and rhBMP-2 that were distributed in the medullar cavity and on the surface of bony trabeculae.
  
  
  CONCLUSIONS
  Tissue-engineered CPC can effectively repair bone defects, with allogenic seeded cells able to grow and differentiate in vivo after transplantation.
authors.affiliation: Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.
authors.forename: Chun-Rong
authors.initials: CR
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Miao
authors.forename: Qun
authors.initials: Q
authors.lastname: Xia
authors.forename: Hong-Chao
authors.initials: HC
authors.lastname: Huang
authors.forename: Chen
authors.initials: C
authors.lastname: Gong
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
authors.forename: Lan-Ying
authors.initials: LY
authors.lastname: Li
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates / Q000737:chemistry*; D002478:Cells, Cultured; D005269:Femur / Q000601:surgery*; D011817:Rabbits; D011994:Recombinant Proteins; D023822:Tissue Engineering / Q000379:methods*; D016212:Transforming Growth Factor beta
chemical_list: D001843:Bone Cements; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; C020243:calcium phosphate