title: Emulsion templated scaffolds with tunable mechanical properties for bone tissue engineering.
abstract: Polymerised High Internal Phase Emulsions (PolyHIPEs) are manufactured via emulsion templating and exhibit a highly interconnected microporosity. These materials are commonly used as thin membranes for 3D cell culture. This study uses emulsion templating in combination with microstereolithography to fabricate PolyHIPE scaffolds with a tightly controlled and reproducible architecture. This combination of methods produces hierarchical structures, where the microstructural properties can be independently controlled from the scaffold macrostructure. PolyHIPEs were fabricated with varying ratios of two acrylate monomers (2-ethylhexyl acrylate (EHA) and isobornyl acrylate (IBOA)) and varying nominal porosity to tune mechanical properties. Young's modulus, ultimate tensile stress (UTS) and elongation at failure were determined for twenty EHA/IBOA compositions. Moduli ranged from 63.01±9.13 to 0.36±0.04MPa, UTS from 2.03±0.33 to 0.11±0.01MPa and failure strain from 21.86±2.87% to 2.60±0.61%. Selected compositions were fabricated into macro-porous woodpile structures, plasma treated with air or acrylic acid and seeded with human embryonic stem-cell derived mesenchymal progenitor cells (hES-MPs). Confocal and two-photon microscopy confirmed cell proliferation and penetration into the micro- and macro-porous architecture. The scaffolds supported osteogenic differentiation of mesenchymal cells and interestingly, the stiffest IBOA-based scaffolds that were plasma treated with acrylic acid promoted osteogenesis more strongly than the other scaffolds.
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, INSIGNEO Institute for in silico medicine, The Pam Liversidge Building, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Owen
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, The Kroto Research Institute, North Campus, Broad Lane, Sheffield S3 7HQ, United Kingdom.
authors.forename: Colin
authors.initials: C
authors.lastname: Sherborne
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, The Kroto Research Institute, North Campus, Broad Lane, Sheffield S3 7HQ, United Kingdom.
authors.forename: Thomas
authors.initials: T
authors.lastname: Paterson
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, The Kroto Research Institute, North Campus, Broad Lane, Sheffield S3 7HQ, United Kingdom.
authors.forename: Nicola H
authors.initials: NH
authors.lastname: Green
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, INSIGNEO Institute for in silico medicine, The Pam Liversidge Building, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, United Kingdom.
authors.forename: Gwendolen C
authors.initials: GC
authors.lastname: Reilly
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, The Kroto Research Institute, North Campus, Broad Lane, Sheffield S3 7HQ, United Kingdom. Electronic address: f.claeyssens@sheffield.ac.uk.
authors.forename: Frederik
authors.initials: F
authors.lastname: Claeyssens
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D001842:Bone and Bones / Q000166:cytology*; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology; D004655:Emulsions; D006801:Humans; D055595:Mechanical Phenomena; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D016062:Porosity; D013718:Tensile Strength; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004655:Emulsions
keywords: Free form fabrication; Mechanical properties; Plasma polymerization; PolyHIPEs; Porosity; Stereolithography