title: Porous zirconia/hydroxyapatite scaffolds for bone reconstruction.
abstract: OBJECTIVE
  Highly porous apatite-based bioceramic scaffolds have been widely investigated as three-dimensional (3D) templates for cell adhesion, proliferation, and differentiation promoting the bone regeneration. Their fragility, however, limits their clinical application especially for a large bone defect.
  
  
  METHODS
  To address the hypothesis that using a ZrO(2)/hydroxyapatite (HAp) composite might improve both the mechanical properties and cellular compatibility of the porous material, we fabricated ZrO(2)/HAp composite scaffolds with different ZrO(2)/HAp ratios, and evaluated their characteristics. In addition, porous ZrO(2)/HAp scaffolds containing bone marrow derived stromal cells (BMSCs) were implanted into critical-size bone defects for 6 weeks in order to evaluate the bone tissue reconstruction with this material.
  
  
  RESULTS
  The porosity of a ZrO(2)/HAp scaffold can be adjusted from 72% to 91%, and the compressive strength of the scaffold increased from 2.5 to 13.8MPa when the ZrO(2) content increased from 50 to 100wt%. The cell adhesion and proliferation in the ZrO(2)/HAp scaffold was greatly improved when compared to the scaffold made with ZrO(2) alone. Moreover, in vivo study showed that a BMSCs-loaded ZrO(2)/HAp scaffold provided a suitable 3D environment for BMSC survival and enhanced bone regeneration around the implanted material.
  
  
  CONCLUSIONS
  We thus showed that a porous ZrO(2)/HAp composite scaffold has excellent mechanical properties, and cellular/tissue compatibility, and would be a promising substrate to achieve both bone reconstruction and regeneration needed in the treatment of large bone defects.
authors.affiliation: Department of Biomaterials Sciences, Osaka University, Osaka, Japan.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: An
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyajima
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakahira
authors.forename: Kyo-Han
authors.initials: KH
authors.lastname: Kim
authors.forename: Satoshi
authors.initials: S
authors.lastname: Imazato
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D001696:Biomechanical Phenomena; D001847:Bone Diseases / Q000601:surgery*; D001854:Bone Marrow Cells / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D024042:Collagen Type I / Q000032:analysis; D019245:Compressive Strength; D018360:Crystallography, X-Ray; D017886:Durapatite / Q000138:chemical synthesis / Q000737:chemistry*; D008297:Male; D051379:Mice; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010006:Osteoblasts / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D053495:Osteopontin / Q000032:analysis; D010294:Parietal Bone / Q000601:surgery; D016062:Porosity; D051381:Rats; D019651:Plastic Surgery Procedures / Q000379:methods*; D017154:Stromal Cells / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; C506897:Spp1 protein, rat; D053495:Osteopontin; D017886:Durapatite; D015040:Zirconium; C028541:zirconium oxide