Computational and experimental characterization of 3D-printed PCL structures toward the design of soft biological tissue scaffolds

• Main Authors: Hailong Liu, Astrid Ahlinder, Mohammed A. Yassin, Anna Finne-Wistrand, T. Christian Gasser
• Format: Article
• Language: English
• Published: Elsevier 2020-03-01
• Series: Materials & Design
• Online Access: http://www.sciencedirect.com/science/article/pii/S0264127520300216

Degradable porous polymeric structures are attractive candidates for biological tissue scaffolds, and adequate mechanical, transport, chemical and biological properties determine their functionality. Aside from the properties of polymer-based materials, the scaffold's meso-structure controls its elasticity at the organ length-scale. This study investigated the effect of the meso-structure on scaffolds' mechanical and transport properties using finite element analysis (FEA) and computational fluid dynamics (CFD). A number of poly (ε-caprolactone) (PCL) - based scaffolds were 3D printed, analyzed by microcomputed tomography (micro-CT) and mechanically tested. We found that the gradient (G) and gradient and staggered (GS) meso-structure designs led to a higher scaffold permeability, a more homogeneous flow inside the scaffold, and a lower wall shear stress (WSS) in comparison with the basic (B) meso-structure design. The GS design resulted in scaffold stiffness as low as 1.07/0.97 MPa under compression/tension, figures that are comparative with several soft tissues. Image processing of micro-CT data demonstrated that the imposed meso-structures could have been adequately realized through 3D printing, and experimental testing validated FEA analysis. Our results suggest that the properties of 3D-printed PCL-based scaffolds can be tuned via meso-structures toward soft tissue engineering applications. The biological function of designed scaffolds should be further explored in-situ studies. Keywords: Scaffold, 3D printing, Meso-structure, Finite element analysis, Computational fluid dynamics, Soft tissue engineering