title: From single fiber to macro-level mechanics: A structural finite-element model for elastomeric fibrous biomaterials.
abstract: In the present work, we demonstrate that the mesoscopic in-plane mechanical behavior of membrane elastomeric scaffolds can be simulated by replication of actual quantified fibrous geometries. Elastomeric electrospun polyurethane (ES-PEUU) scaffolds, with and without particulate inclusions, were utilized. Simulations were developed from experimentally-derived fiber network geometries, based on a range of scaffold isotropic and anisotropic behaviors. These were chosen to evaluate the effects on macro-mechanics based on measurable geometric parameters such as fiber intersections, connectivity, orientation, and diameter. Simulations were conducted with only the fiber material model parameters adjusted to match the macro-level mechanical test data. Fiber model validation was performed at the microscopic level by individual fiber mechanical tests using AFM. Results demonstrated very good agreement to the experimental data, and revealed the formation of extended preferential fiber orientations spanning the entire model space. We speculate that these emergent structures may be responsible for the tissue-like macroscale behaviors observed in electrospun scaffolds. To conclude, the modeling approach has implications for (1) gaining insight on the intricate relationship between fabrication variables, structure, and mechanics to manufacture more functional devices/materials, (2) elucidating the effects of cell or particulate inclusions on global construct mechanics, and (3) fabricating better performing tissue surrogates that could recapitulate native tissue mechanics.
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA; Fondazione RiMED, Italy; DICGIM, University of Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: D'Amore
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Amoroso
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA; Fondazione RiMED, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Gottardi
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hobson
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Carruthers
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Watkins
authors.affiliation: McGowan Institute for Regenerative Medicine, Department of Bioengineering and Surgery, University of Pittsburgh, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Wagner
authors.affiliation: Center for Cardiovascular Simulation, Institute for Computational and Engineering Sciences, Department of Biomedical Engineering, University of Texas at Austin, TX 78712, USA. Electronic address: msacks@ices.utexas.edu.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sacks
mesh_terms: D016880:Anisotropy; D001672:Biocompatible Materials / Q000737:chemistry*; D004548:Elasticity; D020342:Finite Element Analysis; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D011091:Polyesters / Q000737:chemistry; D011093:Polyethylene Terephthalates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011093:Polyethylene Terephthalates; D011108:Polymers; D011140:Polyurethanes