Effect of Porous Substrate Topographies on Cell Dynamics: A Computational Study

Abstract

Controlling cell−substrate interactions via the microstructural characteristics of biomaterials offers an advantageous path for modulating cell dynamics, mechanosensing, and migration, as well as for designing immunemodulating implants, all without the drawbacks of chemical-based triggers. Specifically, recent in vivo studies have suggested that a porous implant's microscale curvature landscape can significantly impact cell behavior and ultimately the immune response. To investigate such cell−substrate interactions, we utilized a 3D computational model incorporating the minimum necessary physics of cell migration and cell−substrate interactions needed to replicate known in vitro behaviors. This model specifically incorporates the effect of membrane tension, which was found to be necessary to replicate in vitro cell behavior on curved surfaces. Our simulated substrates represent two classes of porous materials recently used in implant studies, which have markedly different microscale curvature distributions and pore geometries. We found distinct differences between the overall migration behaviors, shapes, and actin polymerization dynamics of cells interacting with the two substrates. These differences were correlated to the shape energy of the cells as they interacted with the porous substrates, in effect interpreting substrate topography as an energetic landscape interrogated by cells. Our results demonstrate that microscale curvature directly influences cell shape and migration and, therefore, is likely to influence cell behavior. This supports further investigation of the relationship between the surface topography of implanted materials and the characteristic immune response, a complete understanding of which would broadly advance principles of biomaterial design.

The role of the nucleus for cell mechanics: an elastic phase field approach

“…In this respect, the phase field method can be extended relatively easily to 3D, making it possible to consider more complex environments like fibrous network geometries or nonsymmetric constrictions. [95][96][97] The presented method could also be used to describe the role of cell nucleus mechanics in tissues, using the multi-phase field approach. [32][33][34] Note that recently, a new jamming transition due to the presence of nuclei was predicted for tissues by an active foam model.…”