title: Fabrication and characterization of biomimetic collagen-apatite scaffolds with tunable structures for bone tissue engineering.
abstract: The objective of the current study is to prepare a biomimetic collagen-apatite scaffold for improved bone repair and regeneration. A novel bottom-up approach has been developed, which combines a biomimetic self-assembly method with a controllable freeze-casting technology. In this study, the mineralized collagen fibers were generated using a simple one-step co-precipitation method which involved collagen self-assembly and in situ apatite precipitation in a collagen-containing modified simulated body fluid (m-SBF). The precipitates were then subjected to controllable freeze casting, forming scaffolds with either an isotropic equiaxed structure or a unidirectional lamellar structure. These scaffolds were comprised of collagen fibers and poorly crystalline bone-like carbonated apatite nanoparticles. The mineral content in the scaffold could be tailored in the range 0-54wt.% by simply adjusting the collagen content in the m-SBF. Further, the mechanisms of the formation of both the equiaxed and the lamellar scaffolds were investigated, and freezing regimes for equiaxed and lamellar solidification were established. Finally, the bone-forming capability of such prepared scaffolds was evaluated in vivo in a mouse calvarial defect model. It was confirmed that the scaffolds well support new bone formation.
authors.affiliation: Department of Materials Science & Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Zengmin
authors.initials: Z
authors.lastname: Xia
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Yu
authors.forename: Xi
authors.initials: X
authors.lastname: Jiang
authors.forename: Harold D
authors.initials: HD
authors.lastname: Brody
authors.forename: David W
authors.initials: DW
authors.lastname: Rowe
authors.forename: Mei
authors.initials: M
authors.lastname: Wei
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry*; D040761:Biomimetic Materials / Q000138:chemical synthesis*; D001846:Bone Development / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology; D018786:Bone Substitutes / Q000138:chemical synthesis*; D003094:Collagen / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D051379:Mice; D008822:Mice, Transgenic; D012887:Skull Fractures / Q000473:pathology / Q000601:surgery*; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds; D016896:Treatment Outcome
chemical_list: D001031:Apatites; D018786:Bone Substitutes; D003094:Collagen