A whole blood thrombus mimic: Constitutive behavior under simple shear

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Materials Science

Background:

• Deep vein thrombosis and pulmonary embolism impact hundreds of thousands annually in the US.
• Understanding the mechanical factors in pulmonary embolism is crucial for developing effective treatments.
• Existing models often lack the mechanical fidelity to accurately represent thrombus behavior.

Purpose of the Study:

• To develop and characterize an in-vitro thrombus mimic for mechanical testing.
• To investigate the mechanical properties of the mimic under large deformation simple shear.
• To evaluate the influence of coagulation conditions and blood storage on mimic mechanics.

Main Methods:

• Fabrication of homogeneous thrombus mimics using whole blood.
• Quasi-static large deformation simple shear testing of the mimics.
• Analysis of strain-stiffening, Poynting effect, and hysteresis.
• Comparison of Ogden, Neo-Hookean, and Mooney-Rivlin hyperelastic models.

Main Results:

• Thrombus mimics displayed significant strain-stiffening, a negative Poynting effect, and hysteresis.
• Mimic stiffness showed no significant variation with coagulation conditions or blood storage duration.
• The Ogden hyperelastic model demonstrated the best fit for both shear and normal stress data.

Conclusions:

• A reproducible method for creating thrombus mimics suitable for mechanical testing was established.
• The developed mimic provides a valuable tool for studying pulmonary embolism pathophysiology.
• Future work will focus on thrombus maturation and fracture properties to enhance embolization understanding.