Reduced kinematic multiscale model for tissue engineering electrospun scaffolds

DANIEL ENRIQUE CABALLERO; FLORENCIA MONTINI BALLARIN; SANTIAGO URQUIZA; FRONTINI, PATRICIA M.; NAHUEL RULL; JUAN MANUEL GIMENEZ; NICOLÁS BIOCCA

MECHANICS OF MATERIALS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2022

0167-6636

To this day, there is still a need for a direct relationship between the microscopic material properties andnetwork microstructure configuration with the macroscopic mechanical response in order to optimize thedesign loops of biomimetic electrospun grafts. Multiscale mechanical modeling arises as a useful alternative,which allows to represent the individual nanofibers mechanical response and how the interaction betweenfibers results in the final macroscopic behavior. In this work, a micromechanical model that accounts forfiber interaction, progressive straightening (i.e. progressive recruitment) and reorientation is presented. AnRVE is generated by means of a virtual deposition algorithm that mimics the electrospinning process itself,thus obtaining geometries that resemble the observed electrospun microstructure. These geometries were thenvalidated by comparison with analysis of SEM images, taking special interest in the diameter, orientation andtortuosity distributions. Then, an elastic?plastic constitutive law for the nanofibers is implemented along witha simplified kinematic description that results in a significant reduction of the number of Degrees of Freedomof the discretized mechanical equilibrium problem. Finally, the micromechanical model is validated againstuniaxial tensile tests of electrospun PLLA bone-shaped samples, reproducing the experimentally observedbehavior while employing realistic geometric and constitutive parameters to characterize the fibers.