A Numerical Study on the Early-Stage Performance of 3D Composite PLA/316L Scaffolds in Tissue Engineering

In recent years, 3D-printed biocompatible and biodegradable scaffolds used for tissue engineering have attracted great attention as an effective approach for bone repair in critical-size fractures. The surface strains imposed by the loading of the scaffold, the shear wall stresses due to the flow of the interstitial fluid, the material properties, and the geometry of a fused filament fabricated scaffold as well as the final pore size, are some of the crucial parameters that significantly influence the behavior of the cells on the scaffold. In this work, the early-stage performance of a rectangular and four-layer orthogonal scaffold with isometric pores made by polylactic acid PLA/316L with 5% stainless steel particle content, is numerically investigated. The criterion of cell attachment is accomplished via a mechanoregulatory model based on the surface strains and the shear wall stresses of the scaffold imposed by a three-point bending loading and an interstitial flow, respectively. The boundary element method is employed to compute the strain distribution on the scaffold’s surface and then a physics-informed neural network is trained to provide the deformations in the domain given the material properties and the boundary conditions. The element-based finite volume method is utilized to solve the Navier-Stokes equations and evaluate the shear stresses imposed by the fluid flow on the scaffold surface. The predicted surface strain and wall shear stress distribution provide useful insight into the correlation between the structure of the scaffold, the loading type, the cell viability, and differentiation.