Computational and experimental characterization of 3D-printed PCL structures toward the design of soft biological tissue scaffolds. (March 2020)

• Record Type: Journal Article
• Authors: Liu, Hailong; Ahlinder, Astrid; Yassin, Mohammed A.; Finne-Wistrand, Anna; Gasser, T. Christian
• Is Part Of: Materials & design. Volume 188(2020)
• Publication Date: 2020-03
• Subjects: Scaffold -- 3D printing -- Meso-structure -- Finite element analysis -- Computational fluid dynamics -- Soft tissue engineering; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2020.108488
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: 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. Graphical abstract: Unlabelled Image Highlights: A numerical model was constructed to investigate the effect of meso-structure on mechanical and transport properties of scaffold. The designed meso-structures for scaffolds were adequately realized via 3D printing. The computed scaffold stiffness under compression loading agrees well with experimental results. The gradient&staggered design resulted in a low scaffold stiffness (~ 1 MPa). The properties of 3D-printed poly (ε-caprolactone) scaffolds can be tuned via meso-structures toward soft tissue engineering.