Study of biocompatibility and biomechanical properties of composite scaffolds for bone repair

Abstract

Bone repair is interrupted or stalled in nonunion fractures or bone void formation due to removal of bone tumor. The use of bone cements to anchor the free spaces between the bones to restore bone volume and promote bone healing has been a successful treatment modality. However these modalities do not work efficiently as the void fillers. These materials are usually brittle and cannot be reshaped for proper fit. The long-term objective of the study is to develop appropriate composite materials help resolve the biocompatibility and biomechanical problems mentioned above. The current project focuses on understanding the biocompatibility and biomechanical properties of some composites retrieved from a mice model. / The study involves the use of composite materials developed by a private collaborator (whose chemistry is protected). The biomechanical properties of the above mentioned composite polymer were analyzed through both in-vitro and in-vivo studies. The in-vivo studies involved the use of mice femur void model to understand the osteoconductivity of the scaffold by analyzing the variations of bone volume, bone density and total volume in the femur (thigh bone) of mice. / Twenty mice were chosen and divided into four groups of five mice. The first three groups were assigned a biomaterial and the last group was used as a control. The bio-composite scaffold was surgically inserted into the mid-shaft of mouse femur and the mice survived for six weeks before sacrifice. After the set period, the limb with implanted scaffold was harvested and microCT scan was performed to analyze the bone volume fractions and mineral densities within the scaffolds. The preliminary results suggest redevelopment and osteoconductivity in the composite scaffolds. After microCT, 3-point bending biomechanical test on the implanted limbs was performed using a Bose® electroforce testing apparatus. The final assessments of data will be accomplished in the near future.