title: A phenomenological particle-based platelet model for simulating filopodia formation during early activation.
abstract: We developed a phenomenological three-dimensional platelet model to characterize the filopodia formation observed during early stage platelet activation. Departing from continuum mechanics based approaches, this coarse-grained molecular dynamics (CGMD) particle-based model can deform to emulate the complex shape change and filopodia formation that platelets undergo during activation. The platelet peripheral zone is modeled with a two-layer homogeneous elastic structure represented by spring-connected particles. The structural zone is represented by a cytoskeletal assembly comprising of a filamentous core and filament bundles supporting the platelet's discoid shape, also modeled by spring-connected particles. The interior organelle zone is modeled by homogeneous cytoplasm particles that facilitate the platelet deformation. Nonbonded interactions among the discrete particles of the membrane, the cytoskeletal assembly, and the cytoplasm are described using the Lennard-Jones potential with empirical constants. By exploring the parameter space of this CGMD model, we have successfully simulated the dynamics of varied filopodia formations. Comparative analyses of length and thickness of filopodia show that our numerical simulations are in agreement with experimental measurements of flow-induced activated platelets. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Department of Applied Mathematics and Statistics, Stony Brook University, NY, 11794, USA.
authors.forename: Seetha
authors.initials: S
authors.lastname: Pothapragada
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Jawaad
authors.initials: J
authors.lastname: Sheriff
authors.forename: Mark
authors.initials: M
authors.lastname: Livelli
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Slepian
authors.forename: Yuefan
authors.initials: Y
authors.lastname: Deng
authors.forename: Danny
authors.initials: D
authors.lastname: Bluestein
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D003593:Cytoplasm / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D056004:Molecular Dynamics Simulation; D015539:Platelet Activation / Q000502:physiology*; D011554:Pseudopodia / Q000502:physiology*
keywords: coarse-grained molecular dynamics; parallel computing; platelet activation; platelet structure; shear stress