title: Bone augmentation with autologous periosteal cells and two different calcium phosphate scaffolds under an occlusive titanium barrier: an experimental study in rabbits.
abstract: BACKGROUND
  This study used a tissue-engineering approach, which combined autologous periosteal cells with a scaffold material, to promote bone augmentation under an occlusive titanium barrier that was placed on the skull of rabbits. Because the cell-matrix interaction is of key importance in tissue engineering, two different calcium phosphate-based scaffolds were seeded with autologous periosteal cells. One scaffold contained hydroxyapatite, tricalcium phosphate, and collagen; the other scaffold was a beta-tricalcium phosphate structure.
  
  
  METHODS
  The experiment involved 38 rabbits divided into five groups: the two different scaffolds with and without cells and a blood clot only. Prior to implantation, autologous periosteal cells were harvested from the tibia by stripping the periosteum. Cells were cultured, and 1 day before the implantation approximately 20 million cells were collected and seeded onto the scaffolds. Two preformed dome-shaped full titanium barriers were placed subperiosteally onto the frontal and parietal bones of each rabbit. Before placement of the barriers, the different scaffolds, seeded with or without cells, were put on top of the skull. As a negative control, autologous blood was injected into the barriers. Histologic evaluation and histomorphometric analysis were performed after 12 weeks of undisturbed bone growth. Measurements involved the amounts of newly formed tissue and of new bone distinguishing between trabecular bone and osteoid.
  
  
  RESULTS
  No significant differences were found between the four treatment groups (scaffolds with or without cells). However, the amount of new bone tissue found underneath the titanium barriers with scaffolds was significantly higher (P <0.04) than with a blood clot only.
  
  
  CONCLUSIONS
  A better understanding of the mode of action is required to optimize tissue-engineering procedures before entering clinical applications.
authors.affiliation: Department of Periodontology, Catholic University of Leuven, Leuven, Belgium. marina.marechal@tigenix.com
authors.forename: Marina
authors.initials: M
authors.lastname: Maréchal
authors.forename: Jeroen
authors.initials: J
authors.lastname: Eyckmans
authors.forename: Jan
authors.initials: J
authors.lastname: Schrooten
authors.forename: Evert
authors.initials: E
authors.lastname: Schepers
authors.forename: Frank P
authors.initials: FP
authors.lastname: Luyten
authors.forename: Daniel
authors.initials: D
authors.lastname: van Steenberghe
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D017690:Cell Transplantation / Q000379:methods; D002478:Cells, Cultured; D003094:Collagen / Q000502:physiology; D017886:Durapatite / Q000737:chemistry; D048091:Guided Tissue Regeneration / Q000379:methods*; D010012:Osteogenesis / Q000502:physiology; D010521:Periosteum / Q000166:cytology* / Q000502:physiology; D019736:Prostheses and Implants; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000502:physiology; D018709:Statistics, Nonparametric; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D003094:Collagen; D017886:Durapatite