title: Dynamic-mechanical properties of a novel composite intervertebral disc prosthesis.
abstract: Over the past years, a tremendous effort has been made to develop an intervertebral disc (IVD) prosthesis with suitable biological, mechanical and transport properties. However, it has been frequently reported that current prostheses undergo failure mainly due to the mismatch between the mechanical properties of the conventional device and the spine segment to be replaced. The aim of the present work was to develop a poly(2-hydroxyethyl methacrylate)/poly(methyl methacrylate) (PHEMA/PMMA) (80/20 w/w) semi-interpenetrating polymer network (s-IPN) composite hydrogel reinforced with poly(ethylene terephthalate) (PET) fibres, and to investigate the static and dynamic mechanical properties. Filament winding and moulding technologies were employed to obtain the composite IVD prostheses with the unique complex structure that is peculiar to the natural IVD. The compressive properties analysis showed the typical J-shaped stress-strain curve which is displayed by natural IVDs. Compressive modulus varied from 84 to 120 MPa, as a function of the strain rate, and stress was higher than 10 MPa. These values are in the range of those of the natural lumbar IVDs. No failure of the prostheses has occurred during fatigue test performed for ten million cycles in physiological solution. Dynamic mechanical tests have confirmed the composite IVD prostheses exhibited appropriate viscoelastic properties.
authors.affiliation: Institute of Composite and Biomedical Materials, National Research Council and Interdisciplinary Research Centre in Biomaterials, University of Naples Federico II, P. Tecchio 80, 80125 Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gloria
authors.forename: Filippo
authors.initials: F
authors.lastname: Causa
authors.forename: Roberto
authors.initials: R
authors.lastname: De Santis
authors.forename: Paolo Antonio
authors.initials: PA
authors.lastname: Netti
authors.forename: Luigi
authors.initials: L
authors.lastname: Ambrosio
mesh_terms: D032701:Biomimetics; D018786:Bone Substitutes / Q000737:chemistry*; D019245:Compressive Strength; D007403:Intervertebral Disc / Q000502:physiology; D008422:Materials Testing; D019563:Mechanics; D008954:Models, Biological; D019904:Polymethyl Methacrylate / Q000737:chemistry; D019736:Prostheses and Implants; D011474:Prosthesis Design; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D018786:Bone Substitutes; D019904:Polymethyl Methacrylate