title: Elastic-plastic fracture toughness and rising JR-curve behavior of cortical bone is partially protected from irradiation-sterilization-induced degradation by ribose protectant.
abstract: This study tested the hypothesis that pre-treating cortical bone with ribose would protect the rising fracture resistance curve behavior and crack initiation fracture toughness of both bovine and human cortical bone from the degrading effects of γ-irradiation sterilization.
  
  
  
  A ribose pre-treatment (1.8 M for bovine, and 1.2 M for human, in PBS at 60 °C for 24 h) was applied to single-edge notched bending fracture specimens prior to sterilization with a 33 kGy dose of γ-irradiation. Fracture resistance curves were generated with a single specimen method using an optical crack length measurement technique. The effect of the treatment on overall fracture resistance behavior, crack initiation fracture toughness, and tearing modulus was compared with non-irradiated and conventionally irradiation sterilized controls. Hydrothermal isometric tension testing was used to examine collagen network connectivity and thermal stability to explore relationships between collagen network quality and fracture resistance.
  
  
  
  The ribose pre-treatment successfully protected the crack growth initiation fracture toughness of bovine and human bone by 32% and 63%, respectively. The rising JR-curve behavior was also partially protected. Furthermore, collagen connectivity and thermal stability followed similar patterns to those displayed by fracture toughness.
  
  
  
  This paper demonstrates that the fracture toughness of irradiation-sterilized bone tissue can be partially protected with a ribose pre-treatment. This new approach shows potential for the production and clinical application of sterilized allografts with improved mechanical performance and durability.
authors.affiliation: Materials Science and Engineering, University of Toronto, Toronto, ON, Canada; Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld-Tanenbaum Research Institute, Toronto, ON, Canada.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Woodside
authors.affiliation: Materials Science and Engineering, University of Toronto, Toronto, ON, Canada; Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld-Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, ON, Canada; Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, ON, Canada. Electronic address: thomas.willett@uwaterloo.ca.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Willett
mesh_terms: D000818:Animals; D002417:Cattle; D000071538:Cortical Bone / Q000502:physiology* / Q000528:radiation effects*; D050723:Fractures, Bone / Q000517:prevention & control*; D005720:Gamma Rays; D006801:Humans; D012266:Ribose / Q000737:chemistry*; D013242:Sterilization
chemical_list: D012266:Ribose
keywords: Bone; Collagen; Crack growth initiation fracture toughness; Fracture resistance curves; Ribose; γ-Irradiation–sterilization