title: Evaluation of processed bovine cancellous bone matrix seeded with syngenic osteoblasts in a critical size calvarial defect rat model.
abstract: BACKGROUND
  Biologic bone substitutes may offer alternatives to bone grafting procedures. The aim of this study was to evaluate a preformed bone substitute based on processed bovine cancellous bone (PBCB) with or without osteogenic cells in a critical size calvarial defect rat model.
  
  
  METHODS
  Discs of PBCB (Tutobone) were seeded with second passage fibrin gel-immobilized syngenic osteoblasts (group A, n = 40). Cell-free matrices (group B, n = 28) and untreated defects (group C; n=28) served as controls. Specimens were explanted between day 0 and 4 months after implantation and were subjected to histological and morphometric evaluation.
  
  
  RESULTS
  At 1 month, bone formation was limited to small peripheral areas. At 2 and 4 months, significant bone formation, matrix resorption as well as integration of the implants was evident in groups A and B. In group C no significant regeneration of the defects was observed. Morphometric analysis did not disclose differences in bone formation in matrices from groups A and B. Carboxyfluorescine-Diacetate-Succinimidylester (CFDA) labeling demonstrated low survival rates of transplanted cells.
  
  
  CONCLUSIONS
  Osteoblasts seeded into PBCB matrix display a differentiated phenotype following a 14 days cell culture period. Lack of initial vascularization may explain the absence of added osteogenicity in constructs from group A in comparison to group B. PBCB is well integrated and represents even without osteogenic cells a promising biomaterial for reconstruction of critical size calvarial bone defects.
authors.affiliation: Department of Plastic and Hand Surgery, University of Erlangen Medical Center, Erlangen, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Kneser
authors.forename: L
authors.initials: L
authors.lastname: Stangenberg
authors.forename: J
authors.initials: J
authors.lastname: Ohnolz
authors.forename: O
authors.initials: O
authors.lastname: Buettner
authors.forename: J
authors.initials: J
authors.lastname: Stern-Straeter
authors.forename: D
authors.initials: D
authors.lastname: Möbest
authors.forename: R E
authors.initials: RE
authors.lastname: Horch
authors.forename: G B
authors.initials: GB
authors.lastname: Stark
authors.forename: D J
authors.initials: DJ
authors.lastname: Schaefer
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D018786:Bone Substitutes / Q000737:chemistry; D001842:Bone and Bones / Q000473:pathology*; D002417:Cattle; D017690:Cell Transplantation; D005456:Fluorescent Dyes / Q000494:pharmacology; D021621:Imaging, Three-Dimensional; D008297:Male; D015233:Models, Statistical; D016348:Osseointegration; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D005456:Fluorescent Dyes