Design and analysis of the mechanical properties of controllable porous scaffolds for bone tissue engineering

Abstract

The porous scaffold – a substitute for artificial bone – is vital to bone defect repair and bone tissue regeneration in tissue engineering. In consideration of the limitations of few existing design methods, the significant difference between the internal pore structure of porous scaffolds and natural bone microstructure, and the low controllability of design methods. Based on Voronoi-Tessellation (VT) and random function theory, this paper proposed a design method with controllable pore density, adjustable pore shape and size, and heterogeneous pore distribution. The stress change law of porous scaffolds under compression was analyzed using finite element simulation experiments; the relationship between the porosity and the structural strength of porous scaffolds was obtained. Furthermore, the anisotropy of porous scaffolds was studied, and the change law of the macroscopic equivalent elastic modulus with the change in porosity of porous scaffolds was acquired. Under the same porosity, the mechanical properties of the porous scaffold with a uniform pore distribution and the porous scaffold designed in this paper were analyzed and compared; the damage extension laws of two different porous scaffolds were obtained. The results demonstrate that the design method proposed in this paper has high controllability, and the parametric modeling process is both random and controllable. The internal pore structures of porous scaffolds generated by the design method are closer to the microstructure of natural bone tissue – the structural strength satisfies the requirements of artificial implants.

Graphical abstract