title: Reconstruction of segmental bone defects in the rabbit ulna using periosteum encapsulated mesenchymal stem cells-loaded poly (lactic-co-glycolic acid) scaffolds.
abstract: BACKGROUND
  Repair of large bone defects remains a challenge for clinicians. The present study investigated the ability of mesenchymal stem cells (MSCs) and/or periosteum-loaded poly (lactic-co-glycolic acid) (PLGA) to promote new bone formation within rabbit ulnar segmental bone defects.
  
  
  METHODS
  Rabbit bone marrow-derived MSCs (passage 3) were seeded onto porous PLGA scaffolds. Forty segmental bone defects, each 15 mm in length, were created in the rabbit ulna, from which periosteum was obtained. Bone defects were treated with either PLGA alone (group A), PLGA + MSCs (group B), periosteum-wrapped PLGA (group C) or periosteum-wrapped PLGA/MSCs (group D). At 6 and 12 weeks post-surgery, samples were detected by gross observation, radiological examination (X-ray and micro-CT) and histological analyses.
  
  
  RESULTS
  Group D, comprising both periosteum and MSCs, showed better bone quality, higher X-ray scores and a greater amount of bone volume compared with the other three groups at each time point (P < 0.05). No significant differences in radiological scores and amount of bone volume were found between groups B and C (P > 0.05), both of which were significantly higher than group A (P < 0.05).
  
  
  CONCLUSIONS
  Implanted MSCs combined with periosteum have a synergistic effect on segmental bone regeneration and that periosteum plays a critical role in the process. Fabrication of angiogenic and osteogenic cellular constructs or tissue-engineered periosteum will have broad applications in bone tissue engineering.
authors.affiliation: Department of Orthopedic Surgery, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yi-ying
authors.initials: YY
authors.lastname: Qi
authors.forename: Teng-fei
authors.initials: TF
authors.lastname: Zhao
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Xue-song
authors.initials: XS
authors.lastname: Dai
authors.forename: Lie
authors.initials: L
authors.lastname: Niu
authors.forename: Rong-xin
authors.initials: RX
authors.lastname: He
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology; D002478:Cells, Cultured; D019344:Lactic Acid / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D010521:Periosteum / Q000166:cytology*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid