title: Development of nano-hydroxyapatite graft with silk fibroin scaffold as a new bone substitute.
abstract: OBJECTIVE
  This study involves a comparison between the bone regeneration of nano-hydroxyapatite (nHA), as derived from eggshells either with or without silk fibroin scaffolds, and the unfilled control in the rabbit calvarial bony defect model.
  
  
  METHODS
  Sixteen 4-month-old New Zealand white rabbits, with a mean weight of 2.8 kg (range, 2.5-3.0 kg), were used in this experiment. After the formation of bilateral parietal bony defects (diameter, 8.0 mm), either an nHA or an nHA+silk fibroin combination (nHA+silk) was grafted. The control was unfilled defect. The bone regeneration was evaluated by micro-computed tomography (μCT) and histomorphometric analyses at 4 and 8 weeks.
  
  
  RESULTS
  All measured variables of the μCT analysis were significantly higher in the grafted groups (nHA and nHA+silk) than in the unfilled control groups at both 4 and 8 weeks after operation (P < .05). On histomorphometric analysis, there was no significant difference between the groups at 4 weeks after operation. However, the nHA group exerted significantly higher bone regeneration (40.16% ± 8.27%) compared with the unfilled control group (25.66% ± 10.98%) or the nHA+silk group (16.62% ± 3.05%) (P < .05).
  
  
  CONCLUSIONS
  The nHA from eggshells exerted better bone formation than the unfilled control group on both μCT and histomorphometric analyses. Considering the rapid healing in bony defect and easy availability, the nHA from the eggshells could prove to be a good new bone substitute.
authors.affiliation: National Academy of Agricultural Science, RDA, Suwon, Republic of Korea.
authors.forename: HaeYong
authors.initials: H
authors.lastname: Kweon
authors.forename: Kwang-Gill
authors.initials: KG
authors.lastname: Lee
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Chae
authors.forename: Csaba
authors.initials: C
authors.lastname: Balázsi
authors.forename: Soo-Kee
authors.initials: SK
authors.lastname: Min
authors.forename: Jwa-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Je-Yong
authors.initials: JY
authors.lastname: Choi
authors.forename: Seong-Gon
authors.initials: SG
authors.lastname: Kim
mesh_terms: D000818:Animals; D018786:Bone Substitutes; D017886:Durapatite; D005349:Fibroins; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D010012:Osteogenesis; D011817:Rabbits; D047011:Silk; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D018786:Bone Substitutes; D047011:Silk; D005349:Fibroins; D017886:Durapatite