Microstructural constitutive model of active coronary media

Area of Science:

• Cardiovascular Biomechanics
• Vascular Cell Biology
• Biomedical Engineering

Background:

• Vascular smooth muscle cells (VSMCs) are critical in physiological and pathological processes.
• Detailed morphological data on VSMCs, particularly in coronary arteries, is lacking.
• Understanding VSMC structure is key to modeling vascular tissue mechanics.

Purpose of the Study:

• To quantify the dimensions and orientation of swine coronary VSMCs.
• To develop a microstructural constitutive model for active vascular media.
• To link VSMC morphology to the biomechanical response of coronary arteries.

Main Methods:

• Measurement of VSMC dimensions (width, length) and orientation angles at a zero-stress state.
• Development of a microstructure-based active constitutive model.
• Experimental validation using biaxial testing of coronary media.

Main Results:

• VSMC dimensions, aspect ratio, and orientation followed normal distributions.
• VSMCs showed a mean polar angle of 18.7° ± 10.9° relative to the circumferential direction.
• The developed model accurately predicted vasoactivity, linking it to oblique VSMC arrangement and multi-axial contraction.

Conclusions:

• A comprehensive morphological database of swine coronary VSMCs was established.
• The study provides a novel microstructure-based model for active vascular media.
• Findings are essential for accurate structural modeling and understanding the biomechanics of muscular vessels.