A Computational Model for the Geometric and Mechanical Characterization of Electrospun Scaffolds
James Carleton (University of Texas at Austin), Antonio D'Amore (University of Pittsburgh), Gregory Rodin (ICES,UT Austin), Michael Sacks (University of Texas)
Joint Session: Mechanics of cell sheets, multicellular assemblies and tissues and Mechanics and Physics of Biological Cells
Mon 4:20 - 5:40
Barus-Holley 141
Long fiber networks form the microstructure of electrospun scaffolds, which are widely used for mechanical support of growing artificial tissues. Quantitative characterization of such networks is essential for developing a better understanding of their behavior, and for design of optimal tissues. The microscopic geometry of scaffolds may be revealed through the use of imaging, but these images cannot simultaneously resolve microscopic and macroscopic features. Measuring the number of fiber contacts has proven to be particularly difficult and highly dependent on the operator or algorithm, and the variance in these measurements is very large. Analysis of scaffold images is thus insufficient to measure the contact density unambiguously, and analytical and numerical methods must be employed. In this work, we establish relationships between certain macroscopic and microscopic characteristics of scaffolds that reveal the important geometric parameters, and significantly simplify the task of microscopic data acquisition. We also present a simple numerical procedure for capturing essential geometrical and topological features of 3-D scaffolds by creating contacting layers of long, curved fibers, using a self-intersecting random walk inside a periodic box. The scaffold simulations reveal the representative volume element needed to provide an adequate statistical description of the scaffold and aid in microscopic data acquisition by supplementing the image measurements. The generated geometry may be converted into a finite element mesh and used to investigate important classes of problems and quantities of interest, such as general 3-D loading and the evolving 3-D microstructure, including the formation of emergent structures at larger length scales. The result of the parametric studies of the effects and their relationships to network geometry will allow one to understand scaffold mechanical behavior and identify optimal network geometry.