title: Reconstruction of radial bone defects using the reinforced tissue-engineered periosteum: an experimental study on rabbit weightbearing segment.
abstract: BACKGROUND
  The objective of this study was to compare the osteogenic potential of reinforced and conventional tissue-engineered periosteum.
  
  
  METHODS
  Adipose-derived stromal cells of rabbits were induced into osteoblasts. Osteoinduced cells were seeded onto chitosan-tricalcium-phosphate-gelatin (Cs-TCP-Gel) and chitosan (Cs) scaffold, thus constructing the reinforced and conventional tissue-engineered periostea, respectively. Alkaline phosphatase (ALP) and von Kossa staining protocols were used to assess osteoblast phenotype.We surgically created a 15-mm-long bone defect in the right radii of New Zealand rabbits. The defects were treated with reinforced biomimetic periosteum in group A (n = 30) and treated with conventional tissue-engineered periosteum in group B (n = 30).Group C (n = 30) received CS-TCP-Gel scaffold alone, and group D (n = 30) served as untreated side (sham group). Radiologic,histologic, immunohistochemical, and histomorphometric studies were used to analyze healing pattern.
  
  
  RESULTS
  ALP was remarkably expressed in the osteoinduced cells, indicating that osteoblastic differentiation was stable. Extracellular matrix calcification with dark nodule was detected by von Kossa staining. Compared with groups B and C, histologic results demonstrated that de novo osteogenesis proliferated in group A at 4 weeks. This was further confirmed by radiographic findings, which displayed the segmental gap completely healed by mature bone at 12 weeks. Robust expression of bone morphogenetic protein-2 in group A was also evident, whereas group D displayed poor osteogenic performance. Furthermore, histomorphometric and biomechanical results in group A demonstrated statistical significance over those in other groups (p 0.05).
  
  
  CONCLUSIONS
  Our findings show that the reinforced tissue-engineered periosteum is superior to conventional one as a better biomimetic tissue,further indicating that it can repair the weight-bearing defects.
authors.affiliation: Department of Orthopaedic Surgery, General Hospital of Tianjin Medical University, 154 Anshan Avenue, Tianjin, China. honggangguo2000@yahoo.com.cn
authors.forename: Honggang
authors.initials: H
authors.lastname: Guo
authors.forename: Xiaomian
authors.initials: X
authors.lastname: Li
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yuan
authors.forename: Xinlong
authors.initials: X
authors.lastname: Ma
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D002130:Calcium Phosphates / Q000494:pharmacology; D048271:Chitosan / Q000494:pharmacology; D005782:Gels / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D010521:Periosteum / Q000637:transplantation*; D010641:Phenotype; D011817:Rabbits; D011884:Radius / Q000293:injuries / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D016474:Weight-Bearing
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D005782:Gels; D048271:Chitosan; C018392:tricalcium phosphate