Development and Validation of a Novel Method for the Strengthening and Toughening of Irradiation-Sterilized Bone Allografts used in Orthopaedic Reconstructions

Reconstruction of large skeletal defects is a significant and challenging issue. Large defects can occur due to bone cancer, revision arthroplasty and traumatic injuries. Reconstruction using structural bone allograft is often implemented to repair large skeletal defects. However, sterilizing bone allografts by using gamma-irradiation, which is considered as the most effective sterilization method, causes collagen damage and leads to brittle and weak bone. Our lab has begun to develop a technology, by using a ribose treatment prior irradiation, which protects the bone from the irradiation-induced damage. The aim of this project was to test and verify the ribose treatment through extensive mechanical testing to confirm the effects of our novel method. In addition to the mechanical testing, failure and collagen analysis was performed to understand the protective mechanism of the ribose pre-treatment. Ribose pre-treatment improved the mechanical properties of irradiation sterilized human bone in a pre-treatment concentration-dependent manner. The 1.2M ribose pre-treatment provided >100% of ultimate strength of normal controls and protected 76% of the work-to-fracture (toughness) lost in the irradiated controls. Similarly, the ribose pre-treatment improved the thermo-mechanical properties of irradiation-sterilized human bone collagen in a concentration-dependent manner. Greater free radical content and pentosidine content were modified in the ribose treated bone. The pre-treatment also protected 146% of the fatigue life that was lost in the irradiated controls. Furthermore, using the method of pre-treating bone with ribose prior to irradiation sterilization has some potential to improve irradiation sterilized bone allograft quality while also ensuring the effectiveness of the sterilization process. Collectively, our results suggest that ribose treated bone could be used in the clinical setting and providing bone and tissue banks with allografts with mechanical properties similar to or better than native bones to facilitate bone repair and regeneration.Ph.D.2019-12-19 00:00:0