title: Nanoindentation on porous bioceramic scaffolds for bone tissue engineering.
abstract: We report nanoindentation mechanical properties measurements on porous ceramic scaffolds made for tissue engineering applications. The scaffolds have been made from tricalcium phosphate (TCP), hydroxyapatite (HA) nanopowder and mixed powders of HA (50 wt%) and TCP (50 wt%) using the polyurethane sponge method, which produces open porous ceramic scaffolds through replication of a porous polymer template. The scaffolds prepared by this method have a controllable pore size and interconnected pore structure. The crystal structures and morphology of porous scaffolds were determined by X-ray diffraction (XRD) and atomic force microscopy (AFM) respectively. Nanoindentation measurements to a depth of 600 nm showed a Young's modulus value of 10.3 GPa for HA+TCP composite scaffolds and 1.5 GPa for TCP scaffolds. The hardness values were 240 MPa for HA+TCP composites and 21 MPa for TCP sample respectively. The results showed that the mechanical properties of the biodegradable scaffolds can be considerably enhanced with the addition of HA while maintaining the interconnected open pores and pore geometry desirable for bone tissue engineering.
authors.affiliation: Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294-1170, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chowdhury
authors.forename: Vinoy
authors.initials: V
authors.lastname: Thomas
authors.forename: Derrick
authors.initials: D
authors.lastname: Dean
authors.forename: Shane A
authors.initials: SA
authors.lastname: Catledge
authors.forename: Yogesh K
authors.initials: YK
authors.lastname: Vohra
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry; D001842:Bone and Bones / Q000378:metabolism*; D002130:Calcium Phosphates / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D015233:Models, Statistical; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D011208:Powders; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011108:Polymers; D011140:Polyurethanes; D011208:Powders; D017886:Durapatite; C018392:tricalcium phosphate