Layered Elastomeric Fibrous Scaffolds: An In-Silico Study of the Achievable Range of Mechanical Behaviors

Our goal herein is to understand the mechanisms underlying soft tissue and scaffold behaviors by developing a physically based micromechanical model as a means to connect the macroscopic behaviors to the underlying microstructural phenomena. Because of its well-documented capacity for generating elastomeric fibrous materials with a wide range of realizable architectures, the electrospun scaffold was used as the exemplar biomaterial. Fibrous network geometries based on a random walk algorithm were first generated to form the basis for subsequent micromechanical simulations. A basic understanding of randomly oriented fibrous network phenomena was then developed, and subsequently expanded on using networks with aligned fibers. Simulation results were then compared with experimental observations of electrospun scaffolds to evaluate the validity of the simulations. The effects of fiber alignment, tortuosity, and material properties on macroscopic mechanical behavior of the material have been presented both individually and in combination. We have seen that all three aspects of the scaffold network can have significant effects on the macroscopic behavior for different load cases. Overall, accurate representation of detailed fibrous network geometry permitted a greater understanding of the complex mechanisms underlying the macroscopic behavior unique to these biomaterials. Insights gained from such simulations can significantly aid the process of designing scaffold network geometries that result in engineered tissues that function as well as or better than the native tissues they are intended to replace.