A femoral shape porous scaffold bio-nanocomposite fabricated using 3D printing and freeze-drying technique for orthopedic application

The novel bio-nanocomposite scaffold provides a temporary environment for bone growth, and facilitates cell adhesion, growth, and differentiation. In the present study, a 3D printing method is used for fabricating bone scaffolds with wollastonite-hydroxyapatite (WS-HA) composed and chitosan polymer with the polycaprolactone (PCL). Wollastonite (WS) is used as a based ceramic material for chemical stabilizers, which accelerates the healing process, but this material's mechanical strength shows weak mechanical performance. After fabrication of the specimens using solid work and 3D machine, mechanical strength and biological behavior were investigated. Then, scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used to analyze the morphology and phase structure of the architecture. After analyzing the SEM images, the porosity of the scaffolds using Images-J is measured, which indicates that it is similar within the normal bones. The simulated body fluid (SBF) is used for biological tests, and the swelling and absorption tests are performed on the scaffolds which show the hydrophilicity of the components due to their high adsorption power. The atomic structure of the three-component bio-nanocomposite WS-HA is simulated by ABAQUS software and their mechanical and physical properties are extracted. Then, a relationship was proposed to predict the mechanical properties of the WS-HA bio-nanocomposite. Also, a multi-objective problem, with no information related to the desirability of the objectives, is developed and optimized by the Global Criterion Method. Finally, it is concluded that the most suitable scaffold for orthopedic application is a sample with the highest amount of HA with 4.9 MPa compressive strength coated with chitosan.