title: Micro-poro-elasticity of baghdadite-based bone tissue engineering scaffolds: a unifying approach based on ultrasonics, nanoindentation, and homogenization theory.
abstract: Microstructure-elasticity relations for bone tissue engineering scaffolds are key to rational biomaterial design. As a contribution thereto, we here report comprehensive length measuring, weighing, and ultrasonic tests at 0.1MHz frequency, on porous baghdadite (Ca3ZrSi2O9) scaffolds. The resulting porosity-stiffness relations further confirm a formerly detected, micromechanically explained, general relationship for a great variety of different polycrystals, which also allows for estimating the zero-porosity case, i.e. Young modulus and Poisson ratio of pure (dense) baghdadite. These estimates were impressively confirmed by a physically and statistically independent nanoindentation campaign comprising some 1750 indents. Consequently, we can present a remarkably complete picture of porous baghdadite elasticity across a wide range of porosities, and, thanks to the micromechanical understanding, reaching out beyond classical elasticity, towards poroelastic properties, quantifying the effect of pore pressure on the material system behavior.
authors.affiliation: Institute for Mechanics of Materials and Structures, Vienna University of Technology (TU Wien), Karlsplatz 13/E202, A-1040 Vienna, Austria.
authors.forename: Hawraa
authors.initials: H
authors.lastname: Kariem
authors.affiliation: Institute for Mechanics of Materials and Structures, Vienna University of Technology (TU Wien), Karlsplatz 13/E202, A-1040 Vienna, Austria.
authors.forename: Maria-Ioana
authors.initials: MI
authors.lastname: Pastrama
authors.affiliation: Biomaterials and Tissue Engineering Research Unit, School of AMME, The University of Sydney, Sydney 2006, Australia.
authors.forename: Seyed Iman
authors.initials: SI
authors.lastname: Roohani-Esfahani
authors.affiliation: Australian Institute for Musculoskeletal Science, NorthWest Academic Centre, Department of Medicine, University of Melbourne, Victoria 3021, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Pivonka
authors.affiliation: Biomaterials and Tissue Engineering Research Unit, School of AMME, The University of Sydney, Sydney 2006, Australia.
authors.forename: Hala
authors.initials: H
authors.lastname: Zreiqat
authors.affiliation: Institute for Mechanics of Materials and Structures, Vienna University of Technology (TU Wien), Karlsplatz 13/E202, A-1040 Vienna, Austria. Electronic address: christian.hellmich@tuwien.ac.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Hellmich
mesh_terms: D001846:Bone Development; D002516:Ceramics / Q000737:chemistry*; D004548:Elasticity; D036103:Nanotechnology; D016062:Porosity; D017640:Silicates / Q000737:chemistry*; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: C000592768:Ca(3)ZrSi(2)O(9); D017640:Silicates
keywords: Baghdadite; Micromechanics; Nanoindentation; Scaffold; Ultrasound