title: In vivo performance of bilayer hydroxyapatite scaffolds for bone tissue regeneration in the rabbit radius.
abstract: The objective of this study was to investigate the in vivo biomechanical performance of bone defects implanted with novel bilayer hydroxyapatite (HAp) scaffolds that mimic the cortical and cancellous organization of bone. The scaffolds maintained architectural continuity in a rabbit radius segmental defect model and were compared to an untreated defect group (negative control) and autologous bone grafts (positive control). Micro-CT evaluations indicated total bone and scaffold volume in the experimental group was significantly greater than the defect group but lesser than the autologous bone graft treatment. The flexural toughness of the scaffold and the autograft groups was significantly greater than the flexural toughness of the defect group. Interestingly, the absolute density of the bone mineral as well as calcium to phosphorus (Ca/P) ratio in that mineral for the scaffold and autograft contralateral bones was significantly higher than those for the defect contralaterals suggesting that the scaffolds contributed to calcium homeostasis. It was concluded from this study that new bone regenerated in the bilayer HAp scaffolds was comparable to the empty defects and while the HAp scaffolds provided significant increase in modulus when compared to empty defect and their flexural toughness was comparable to autografts after 8 weeks of implantation.
authors.affiliation: Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3400 Rawley E. Chambers Ave., Fort Sam Houston, TX 78234, USA. teja.guda@gmail.com
authors.forename: Teja
authors.initials: T
authors.lastname: Guda
authors.forename: John A
authors.initials: JA
authors.lastname: Walker
authors.forename: Beth E
authors.initials: BE
authors.lastname: Pollot
authors.forename: Mark R
authors.initials: MR
authors.lastname: Appleford
authors.forename: Sunho
authors.initials: S
authors.lastname: Oh
authors.forename: Joo L
authors.initials: JL
authors.lastname: Ong
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wenke
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D001861:Bone Regeneration; D018786:Bone Substitutes; D016025:Bone Transplantation; D001842:Bone and Bones / Q000473:pathology*; D006882:Hydroxyapatites / Q000737:chemistry; D016062:Porosity; D011817:Rabbits; D012038:Regeneration; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D018786:Bone Substitutes; D006882:Hydroxyapatites