Computational predictions of the tensile properties of electrospun fibre meshes: Effect of fibre diameter and fibre orientation

Abstract

The mechanical properties of biomaterial scaffolds are crucial for their efficacy in tissue engineering and regenerative medicine. At the microscopic scale, the scaffold must be sufficiently rigid to support cell adhesion, spreading, and normal extracellular matrix deposition. Concurrently, at the macroscopic scale the scaffold must have mechanical properties that closely match those of the target tissue. The achievement of both goals may be possible by careful control of the scaffold architecture. Recently, electrospinning has emerged as an attractive means to form fused fibre scaffolds for tissue engineering. The diameter and relative orientation of fibres affect cell behaviour, but their impact on the tensile properties of the scaffolds has not been rigorously characterized. To examine the structure-property relationship, electrospun meshes were made from a polyurethane elastomer with different fibre diameters and orientations and mechanically tested to determine the dependence of the elastic modulus on the mesh architecture. Concurrently, a multiscale modelling strategy developed for type I collagen networks was employed to predict the mechanical behaviour of the polyurethane meshes. Experimentally, the measured elastic modulus of the meshes varied from 0.56 to 3.0 MPa depending on fibre diameter and the degree of fibre alignment. Model predictions for tensile loading parallel to fibre orientation agreed well with experimental measurements for a wide range of conditions when a fitted fibre modulus of 18 MPa was used. Although the model predictions were less accurate in transverse loading of anisotropic samples, these results indicate that computational modelling can assist in design of electrospun artificial tissue scaffolds.

Tuning electrospinning parameters for production of 3D-fiber-fleeces with increased porosity for soft tissue engineering applications

“…Young's moduli of the scaffolds were shown to depend on the polymer that they were composed of, but interestingly it was also found to be dependent on the scaffold morphology, confirming findings already reported (Boland et al, 2001;Baker et al, 2008;Choi et al, 2008;Stylianopoulos et al, 2008;Aviss et al, 2010). The Young's modulus increased slightly with the fiber diameter for thin PLGA fibers composing the scaffolds while it decreased in scaffolds with increased porosity.…”

Pcl/Peg Electrospun Fibers as Drug Carriers for the Controlled Delivery of Dipyridamole

“…The influence of DPA and PEG on the solution's electrical conductivity as well as on the average fiber diameter can also affect the mechanical properties. The decrease in the average fiber diameter and minor change in the general alignment and structure of the fibers affect mechanical properties [34]. Moreover, differences in intermolecular interactions between the polymers might explain differences in mechanical properties.…”

The anisotropic mechanical behaviour of electro-spun biodegradable polymer scaffolds: Experimental characterisation and constitutive formulation

“…fibre diameter, orientation, packing density), stiffness of fibres and macroscopic mechanical response under a variety of loading conditions (Chandran and Barocas, 2006;Hatami-Marbini and Picu, 2009;Pence et al, 2008;Rizvi and Pal, 2014;Sander et al, 2009;Sastry et al, 1998;Sastry et al, 2001;Silberstein et al, 2012;Stylianopoulos et al, 2008;Wu and Dzenis, 2005). These models, often based on multiscale approaches using volume-averaging theories (Stylianopoulos et al, 2008) are typically restricted to two-dimensional arrangements and/or do not easily generalise to threedimensional continua. Although very insightful, in a finite element context, these approaches are not the most appropriate to simulate the macroscopic behaviour of whole structures made of fibrous network such as those generated by electro-spinning processes because of the high computational cost in simulating their behaviour.…”