Effect of Fiber Diameter and Alignment of Electrospun Polyurethane Meshes on Mesenchymal Progenitor Cells

Abstract

Effective strategies to guide cell alignment and the deposition of an oriented extracellular matrix are critical for the development of anisotropic engineered tissues suitable for the repair of ligament defects. Electrospinning is a promising means to create meshes that can align adherent cells, but the effect of fiber mesh architecture on differentiation has not been examined closely. Therefore, the goal of this study was to determine the effect of fiber diameter and the degree of fiber alignment on mesenchymal progenitor cell morphology, proliferation, and ligament gene expression. Specifically, a poly(ester urethane)urea elastomer was electrospun onto rigid supports under conditions designed to independently vary the mean fiber diameter (from 0.28 to 2.3 microm) and the degree of fiber alignment. Bone marrow stromal cells--seeded onto supported meshes--adhered to and proliferated on all surfaces. Cells assumed a more spindle-shaped morphology with increasing fiber diameter and degree of fiber alignment, and oriented parallel to fibers on aligned meshes. Expression of the ligament markers collagen 1alpha1, decorin, and tenomodulin appeared to be sensitive to fiber diameter and greatest on the smallest fibers. Concurrently, expression of the transcription factor scleraxis appeared to decrease with increasing fiber alignment. These results suggest that the formation of a ligament-like tissue on electrospun scaffolds is enhanced when the scaffolds consist of aligned submicron fibers.

Advances in Regenerative Medicine

“…Advanced manufacturing techniques can be used to control the spatial sub-micrometric internal architecture in engineered tissues, manipulating the scaffold topography on the length scale of the stem cell niche and smaller. It has been demonstrated that nanofibrous polymeric scaffolds offer to the cells biomimetic configurations that resembles ECM collagen fibers in their ability to support the differentiation of progenitor/stem cells along adipogenic, chondrogenic, and osteogenic lineages (Yang, Murugan et al 2005;Badami, Kreke et al 2006;Bashur, Shaffer et al 2009;Wise, Yarin et al 2009). Nanotechnology, or the use of nanomaterials, may help to realize materials mimicking surface properties (including topography, energy, etc) of natural tissues.…”

Cell-Biomaterial Interactions Reproducing a Niche

“…Advanced manufacturing techniques can be used to control the spatial sub-micrometric internal architecture in engineered tissues, manipulating the scaffold topography on the length scale of the stem cell niche and smaller. It has been demonstrated that nanofibrous polymeric scaffolds offer to the cells biomimetic configurations that resembles ECM collagen fibers in their ability to support the differentiation of progenitor/stem cells along adipogenic, chondrogenic, and osteogenic lineages (Yang, Murugan et al 2005;Badami, Kreke et al 2006;Erisken, Kalyon et al 2008;Bashur, Shaffer et al 2009;Wise, Yarin et al 2009). Nanotechnology, or the use of nanomaterials, may help to realize materials mimicking surface properties (including topography, energy, etc) of natural tissues.…”

Static and Cyclic Mechanical Loading of Mesenchymal Stem Cells on Elastomeric, Electrospun Polyurethane Meshes

“…However, these materials-typically prepared by melt-or wetspinning-consist of 25-200 lm diameter fibers that are larger than mammalian cells and do not necessarily present a topography to guide cell alignment. In contrast, fibers produced by electrospinning have diameters of 0.1-5 lm [8], can guide cell alignment [9][10][11], and modulate development of organized extracellular matrix (ECM) [12][13][14]. For example, Chaurey et al showed that as the diameters of aligned fibers were increased from 0.1 to 0.8 lm, the cell alignment also increased [15].…”