title: Mechanical Properties of Plasma Immersion Ion Implanted PEEK for Bioactivation of Medical Devices.
abstract: Plasma immersion ion implantation (PIII) is used to modify the surface properties of polyether ether ketone for biomedical applications. Modifications to the mechanical and chemical properties are characterized as a function of ion fluence (treatment time) to determine the suitability of the treated surfaces for biological applications. Young's modulus and elastic recovery were found to increase with respect to treatment time at the surface from 4.4 to 5.2 MPa and from 0.49 to 0.68, respectively. The mechanical properties varied continuously with depth, forming a graded layer where the mechanical properties returned to untreated values deep within the layer. The treated surface layer exhibited cracking under cyclical loads, associated with an increased modulus due to dehydrogenation and cross-linking; however, it did not show any sign of delamination, indicating that the modified layer is well integrated with the substrate, a critical factor for bioactive surface coatings. The oxygen concentration remained unchanged at the surface; however, in contrast to ion implanted polymers containing only carbon and hydrogen, the oxygen concentration within the treated layer was found to decrease. This effect is attributed to UV exposure and suggests that PIII treatments can modify the surface to far greater depths than previously reported. Protein immobilization on PIII treated surfaces was found to be independent of treatment time, indicating that the surface mechanical properties can be tuned for specific applications without affecting the protein coverage. Our findings on the mechanical properties demonstrate such treatments render PEEK well suited for use in orthopedic implantable devices.
authors.affiliation: Applied and Plasma Physics, School of Physics, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Edgar A
authors.initials: EA
authors.lastname: Wakelin
authors.affiliation: School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Ali
authors.initials: A
authors.lastname: Fathi
authors.affiliation: School of Applied Sciences, RMIT University , GPO BOX 476, Melbourne, Victoria 3001, Australia.
authors.forename: Masturina
authors.initials: M
authors.lastname: Kracica
authors.affiliation: School of Molecular Bioscience, The University of Sydney , Sydney, New South Wales 2006, Australia.|Charles Perkins Centre, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Giselle C
authors.initials: GC
authors.lastname: Yeo
authors.affiliation: Applied Materials Group, Heart Research Institute, Newtown 2042 and Sydney Medical School, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Wise
authors.affiliation: School of Molecular Bioscience, The University of Sydney , Sydney, New South Wales 2006, Australia.|Charles Perkins Centre, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Weiss
authors.affiliation: School of Applied Sciences, RMIT University , GPO BOX 476, Melbourne, Victoria 3001, Australia.
authors.forename: Dougal G
authors.initials: DG
authors.lastname: McCulloch
authors.affiliation: School of Chemical and Biomolecular Engineering, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Fariba
authors.initials: F
authors.lastname: Dehghani
authors.affiliation: Applied and Plasma Physics, School of Physics, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Mckenzie
authors.affiliation: Applied and Plasma Physics, School of Physics, The University of Sydney , Sydney, New South Wales 2006, Australia.
authors.forename: Marcela M M
authors.initials: MM
authors.lastname: Bilek
mesh_terms: D001577:Benzophenones; D004548:Elasticity; D004797:Enzyme-Linked Immunosorbent Assay; D004864:Equipment and Supplies; D055767:Immobilized Proteins / Q000378:metabolism; D007477:Ions; D007659:Ketones / Q000737:chemistry*; D055595:Mechanical Phenomena; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D058626:Plasma Gases / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D013718:Tensile Strength; D014333:Tropoelastin
chemical_list: D001577:Benzophenones; D055767:Immobilized Proteins; D007477:Ions; D007659:Ketones; D058626:Plasma Gases; D011108:Polymers; D014333:Tropoelastin; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D009584:Nitrogen; D010100:Oxygen
keywords: Elastic modulus; PEEK; biocompatible; ion modification; nanoindentation; plasma immersion ion implantation; polyether ether ketone