title: Time-dependent changes in dynamic mechanical properties of irradiated bone.
abstract: The increased use of allograft tissue for musculoskeletal repair has brought more focus to the safety of allogenic tissue and the efficacy of various sterilization techniques. The currently available literature contains few examples of studies on long-lasting strains of bones but no example for irradiated bones. In this study the bovine femurs from a 2-year-old animal were machine cut and irradiated with the doses of 10, 15, 25, 35, 45 and 50 kGy. The dynamic mechanical analysis was performed at 1 Hz at the room temperature in a 3-point bending configuration for 2880 minutes. The final values of E' and E″ were dose independent but they were reached at different periods. For this reason, so called "critical point" was introduced for the further analysis. All the examined sample groups were characterized by statistically significant lower values of the critical point in comparison with the control samples (p<0.05) but the biggest differences were observed between the control samples and the samples irradiated with the doses of 10, 15 and 25 kGy. Current results and literature review suggest that the dose of 35 kGy is the optimal dose for ionizing radiation sterilization.
authors.affiliation: Department of Oncology, Poznan University of Medical Sciences, Poznan, Poland.|Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, Poznan, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Mardas
authors.affiliation: Department of Biophysics, Poznan University of Medical Sciences, Poznan, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Kubisz
authors.affiliation: Department of Physics, Adam Mickiewicz University, Poznan, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Biskupski
authors.affiliation: Department of Physics, Adam Mickiewicz University, Poznan, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Mielcarek
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology* / Q000528:radiation effects; D000818:Animals; D016025:Bone Transplantation / Q000379:methods; D002417:Cattle; D019245:Compressive Strength / Q000502:physiology / Q000528:radiation effects; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D055119:Elastic Modulus / Q000502:physiology / Q000528:radiation effects; D005269:Femur / Q000502:physiology* / Q000528:radiation effects* / Q000637:transplantation; D066298:In Vitro Techniques; D008954:Models, Biological; D011829:Radiation Dosage; D013242:Sterilization / Q000379:methods; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors
keywords: Bone; DMA (Dynamic Mechanical Analysis); radiation; sterilization