Fabrication, experimental study, and 2-D finite element computational homogenization of bone scaffolds under uniaxial and biaxial compressive loadings

Abstract

In this research, a novel nanocomposite bone scaffold made up of Gelatin and Polypyrrole biopolymers and Akermanite and Magnetite bioceramics was fabricated utilizing the freeze-drying method. Fourier Transform Infrared (FTIR) spectroscopy and X-ray Diffraction (XRD) analysis were employed. The existing functional groups and crystalline phases were identified. Microscopic images were taken, and the mean pore cell size was 165.62 µm. According to the results of the liquid displacement method, the porosity was 68% ± 3%. The fabricated scaffolds showed maximum swelling of 1012% during 140 h. The bioactivity was monitored, and the formed Apatite layers were seen in microscopic images. The MTT assay was conducted by Osteoblast cells culture, and after 3 days, 100% cell viability was recorded. 2-D porous multiphase Representative Volume Elements (RVEs) were generated employing the modified Random Sequential Adsorption (mRSA) algorithm. Afterward, we imposed periodic boundary conditions on the boundaries of the RVEs. The homogenized elastic modulus along the X-axis was 14.81 kPa in biaxial compression. In this loading state, homogenized Young’s modulus along the Y-axis was 13.7 kPa. Homogenized Young’s modulus along Y-axis direction under uniaxial loading was 12.54 kPa. According to the micromechanical modeling results, non-isotropic behavior from such scaffolds was seen.