Modelling the Influence of Protein Expression Levels on the Mechanical Properties of Femur Bone

Abstract

Most abundantly found structural protein in our connective tissue, bone, and skin etc. are collagen. Many investigations on the collagen to predict its structural and mechanical properties has been done over the decades, but none of them were universally accepted. [beta]-tricalciumphosphate is yet another organic matrix material found in bone for holding and binding the protein fibers and provide its hardness to the flexible frame structure of the proteins. Collagen is well known for its tensile strength and delivers it to its connecting tissue and other parts of the flexible frame structure. In this work, an approach has been made and investigating the impact of collagen protein on the mechanical behavior at its microscopic level and then implemented in the macro structured femur bone. A unit cell prepared in which collagen protein are staggered at the center and surrounded by fibers at the corners. Dimensions of collagen fiber are in the range of 0.01 |im to 0.125 |im at different volume fraction ranging from 10% to 50% of the collagen fibers. Evaluation of Equivalent material properties using Homogenization based Numerical Simulation used for the study of the influence of protein expression level on stress and strain distribution in femur bone by varying the collagen volume level and its diameter. Relationship for mechanical properties of collagen in bone and its geometrical parameters has been predicted in this work. Mechanical properties are decreasing with the increase in the volume fraction of the collagen level while shows increase in it by an increase in the fiber diameter up to particular value and no change with further increase. The effect of collagen fibrils diameter is not as dominant as the change in volume of fraction shows over the stress and strain in the femur bone. Stress values are ranging from 16.122 MPa to 15.612 MPa by increasing the volume fraction from 10% to 50%.