Design and Mechanical Compatibility of Nylon Bionic Cancellous Bone Fabricated by Selective Laser Sintering

Abstract

In order to avoid the stress shielding phenomenon in orthopedic bionic bone implantation, it is necessary to consider the design of mechanical compatible implants imitating the host bone. In this study, we developed a novel cancellous bone structure design method aimed at ensuring the mechanical compatibility between the bionic bone and human bone by means of computer-aided design (CAD) and finite element analysis technology (specifically, finite element modeling (FEM)). An orthogonal lattice model with volume porosity between 59% and 96% was developed by means of CAD. The effective equivalent elastic modulus of a honeycomb structure with square holes was studied by FEM simulation. With the purpose of verifying the validity of the cancellous bone structure design method, the honeycomb structure was fabricated by selective laser sintering (SLS) and the actual equivalent elastic modulus of the honeycomb structure was measured with a uniaxial compression test. The experimental results were compared with the FEM values and the predicted values. The results showed that the stiffness values of the designed structures were within the acceptable range of human cancellous bone of 50–500 MPa, which was similar to the stiffness values of human vertebrae L1 and L5. From the point of view of mechanical strength, the established cellular model can effectively match the elastic modulus of human vertebrae cancellous bone. The functional relationship between the volume porosity of the nylon square-pore honeycomb structure ranging from 59% to 96% and the effective elastic modulus was established. The effect of structural changes related to the manufacture of honeycomb structures on the equivalent elastic modulus of honeycomb structures was studied quantitatively by finite element modeling.

The application of biomaterials in osteogenesis: A bibliometric and visualized analysis

“…Major surface modification techniques of biomaterials included sandblasting, acid-etching, de-alloying, and micro-arc oxidation, etc (Chou et al, 2017;Okulov et al, 2020;Zhang et al, 2021). Novel structural design of biomaterials included porous architecture design, individualized three-dimensional (3D) printing, and biomimetic design, etc (Wong, 2016;Yuan et al, 2019;Chen et al, 2021). However, at present, there is still a lack of systematic, intuitive, and visualized analysis to help researchers analyze the research trends in the field of biomaterials research in osteogenesis.…”

Laser Sintering Approaches for Bone Tissue Engineering

“…Additionally, the bioinert nature of PA could have played a role in reducing the tissue ingrowth. Similarly, PA was used in a recent study that employed an SLS technique to overcome stress shielding by generating porous, biomimetic trabecular-like bone scaffolds [110]. To address this, a porous honeycomb structure was generated through SLS using PA-66.…”

Effect of Sterilization on the Dimensional and Mechanical Behavior of Polylactic Acid Pieces Produced by Fused Deposition Modeling

“…In the face of these facts, increasing attention has been drawn to the use of more affordable, FDA-approved materials for FDM processing, such as polylactic acid (PLA) [ 35 , 36 ] and nylon [ 37 ], which have been reported for the manufacture of MDs for orthopedic implants and scaffolds. Despite their low cost and biocompatibility, PLA and nylon-based MDs produced by FDM are still susceptible to physical and dimensional damage upon exposure to high-temperature steam sterilization [ 38 ].…”