title: Fabrication of intrafibrillar and extrafibrillar mineralized collagen/apatite scaffolds with a hierarchical structure.
abstract: A biomimetic collagen-apatite (Col-Ap) scaffold resembling the composition and structure of natural bone from the nanoscale to the macroscale has been successfully prepared for bone tissue engineering. We have developed a bottom-up approach to fabricate hierarchically biomimetic Col-Ap scaffolds with both intrafibrillar and extrafibrillar mineralization. To achieve intrafibrillar mineralization, polyacrylic acid (PAA) was used as a sequestrating analog of noncollagenous proteins (NCPs) to form a fluidic amorphous calcium phosphate (ACP) nanoprecursor through attraction of calcium and phosphate ions. Sodium tripolyphosphate was used as a templating analog to regulate orderly deposition of apatite within collagen fibrils. Both X-ray diffraction and Fourier transform infrared spectroscopy suggest that the mineral phase was apatite. Field emission scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction confirmed that hierarchical collagen-Ap scaffolds were produced with both intrafibrillar and extrafibrillar mineralization. Biomimetic Col-Ap scaffolds with both intrafibrillar and extrafibrillar mineralization (IE-Col-Ap) were compared with Col-Ap scaffolds with extrafibrillar mineralization only (E-Col-Ap) as well as pure collagen scaffolds in vitro for cellular proliferation using MC3T3-E1 cells. Pure collagen scaffolds had the highest rate of proliferation, while there was no statistically significant difference between IE-Col-Ap and E-Col-Ap scaffolds. Thus, the bottom-up biomimetic fabrication approach has rendered a group of promising Col-Ap scaffolds, which bear high resemblance to natural bone in terms of composition and structure.
authors.affiliation: Institute of Materials Science, University of Connecticut, 97 North Eagleville Rd, Unit 3136, Storrs, Connecticut, 06269.
authors.forename: Changmin
authors.initials: C
authors.lastname: Hu
authors.affiliation: Department of Materials Science and Engineering, University of Connecticut, 97 North Eagleville Rd, Unit 3136, Storrs, Connecticut, 06269.
authors.forename: Michael
authors.initials: M
authors.lastname: Zilm
authors.affiliation: Institute of Materials Science, University of Connecticut, 97 North Eagleville Rd, Unit 3136, Storrs, Connecticut, 06269.|Department of Materials Science and Engineering, University of Connecticut, 97 North Eagleville Rd, Unit 3136, Storrs, Connecticut, 06269.
authors.forename: Mei
authors.initials: M
authors.lastname: Wei
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry*; D032701:Biomimetics; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry; D002460:Cell Line; D049109:Cell Proliferation; D003094:Collagen / Q000737:chemistry*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D018786:Bone Substitutes; D002130:Calcium Phosphates; C519480:amorphous calcium phosphate; D003094:Collagen
keywords: amorphous calcium phosphate nanoprecursors; bottom-up approach; hierarchical scaffolds; intrafibrillar mineralization