From imaging to computational domains for physics-driven molecular biology simulations: Hindered diffusion in platelet masses.

Journal: PLoS computational biology
Published Date:

Abstract

When formed in vivo, murine hemostatic thrombi exhibit a heterogeneous architecture comprised of distinct regions of densely and sparsely packed platelets. In this study, we utilize high-resolution electron microscopy alongside machine learning and physics-based simulations to investigate how such clot microstructure impacts molecular diffusivity. We used Serial Block Face - Scanning Electron Microscopy (SBF-SEM) to image select volumes of hemostatic masses formed in a mouse jugular vein, producing high-resolution 2D images. Images were segmented using machine learning software (Cellpose), whose training was augmented by manually segmented images. The segmented images were then utilized as 2D computational domains for Lattice Kinetic Monte-Carlo (LKMC) simulations. This process constitutes a computational pipeline that combines purely data-derived biological domains with physics-driven simulations to estimate how molecular movement is hindered in a hemostatic platelet mass. Using our pipeline, we estimated that the 2D hindered diffusion rates of a globular protein range from 2% to 40% of the unhindered rate, with denser packing regions lending to lower molecular diffusivity. These data suggest that coagulation reactions rates, thrombin generation and activity, as well as platelet releasate activity may be drastically impacted by the internal geometry of a hemostatic thrombus.

Authors

  • Catherine House
    Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
  • Ziyi Huang
    Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
  • Kaushik N Shankar
    Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
  • Sandra J Young
    Independent Researcher, Philadelphia, Pennsylvania, United States of America.
  • Meghan E Roberts
    Cardeza Foundation for Hematological Research, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America.
  • Scott L Diamond
    Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia PA 19104, USA.
  • Maurizio Tomaiuolo
    Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America.
  • Timothy J Stalker
    Cardeza Foundation for Hematological Research, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America.
  • Lu Lu
    China School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China.
  • Talid Sinno
    Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia PA 19104, USA.

Keywords

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