A prestressed intracellular biomechanical model for the platelet to capture the disc-to-sphere morphological change from resting to activated state.

This paper proposes a biomechanical platelet model with an intracellular prestressed assumption. The platelet structure is composed of a membrane cortex and a marginal band (MB). The membrane cortex is assumed in a spherical shape in its initial state and modeled using spring-network elements widely used for the similar membrane structure of red blood cells. The MB is modeled as one solid torus, which employs the hyperelastic material model, and is confined inside the cortex through a contact model. In the initial equilibrium state, the platelet has a stable, flat, and discoid shape. Upon activation, the possible mechanism of the unbinding rate of crosslink between the microtubules (MTs) is assumed to break the homogeneous stiffness of the MB, which causes the platelet to have a disc-to-sphere morphological transition. The numerical results and the experimental images of the MBs show good agreement. The proposed model provides a novelty in relating the mechanical property changes of the MB to the platelet morphological changes upon activation, thus, can provide a possible engineering tool to reveal the intriguing behavior of platelet upon activation.