Investigation of 2D and 3D electrospun scaffolds intended for tendon repair

Abstract

Two-dimensional (2D) electrospun fibre mats have been investigated as fibrous sheets intended as biomaterials scaffolds for tissue repair. It is recognised that tissues are three-dimensional (3D) structures and that optimisation of the fabrication process should include both 2D and 3D scaffolds. Understanding the relative merits of the architecture of 2D and 3D scaffolds for tendon repair is required. This study investigated three different electrospun scaffolds based on poly(ε-caprolactone) fibres intended for repair of injured tendons, referred to as; 2D random sheet, 2D aligned sheet and 3D bundles. 2D aligned fibres and 3D bundles mimicked the parallel arrangement of collagen fibres in natural tendon and 3D bundles further replicated the tertiary layer of a tendon's hierarchical configuration. 3D bundles demonstrated greatest tensile properties, being significantly stronger and stiffer than 2D aligned and 2D random fibres. All scaffolds supported adhesion and proliferation of tendon fibroblasts. Furthermore, 2D aligned sheets and 3D bundles allowed guidance of the cells into a parallel, longitudinal arrangement, which is similar to tendon cells in the native tissue. With their superior physical properties and ability to better replicate tendon tissue, the 3D electrospun scaffolds warrant greater investigation as synthetic grafts in tendon repair.

Dynamic loading of electrospun yarns guides mesenchymal stem cells towards a tendon lineage

“…The strips were then manually twisted along their lengths to create yarns of electrospun fibres (Ø ~200 µm) (as previously described in Bosworth et al, 2013). …”

“…Capable of supporting a wide range of cell types, electrospun scaffolds have been investigated for the repair and regeneration of bone (Yang et al, 2013), nerves (Koh et al, 2010), bladder (Stankus et al, 2008), amongst many others. Electrospun scaffolds that possess a parallel arrangement of fibres are currently being researched for the repair of damaged tendons (Bosworth et al, 2013). In this case, three-dimensional electrospun fibrous yarns – a continuous strand of twisted fibres – were found to be superior scaffolds compared to the more common two-dimensional sheets of aligned fibres for this particular tissue type.…”

Tendon grafts: their natural history, biology and future development

“…Modern biomaterials aim to facilitate the tendon formation process through surface topography and biomimicry (Kloczko et al, 2015), but have had mixed success owing to the unpredictable characteristics of biomaterials left in vivo over time. Studies have shown good tendon-like morphology in vitro (Bosworth et al, 2013) and promising engraftment in vivo (Chen et al, 2012a) (Figure 5(D)). It is difficult to show whether biomaterial constructs offer a biological tendon replacement or simply facilitate a more organized scarring process (Czaplewski et al, 2014).…”

Multiscale Poly-(ϵ-caprolactone) Scaffold Mimicking Non-linearity in Tendon Tissue Mechanics

“…11 A number of researchers have utilized electrospinning to attempt to exploit the electrospun fiber benefits for regenerative medicine applications. 12–15 …”