Frictional Behavior of Individual Vascular Smooth Muscle Cells Assessed By Lateral Force Microscopy

Area of Science:

• Biotribology
• Cellular mechanics
• Biomaterials science

Background:

• Studying cell and tissue friction is crucial for medical device development.
• Understanding micro-scale friction between rigid surfaces and cells is clinically relevant.
• Existing methods lack direct measurement of cellular frictional properties.

Purpose of the Study:

• To develop and apply a technique for measuring the frictional properties of individual vascular smooth muscle cells (VSMCs).
• To investigate the influence of cellular structure on friction using atomic force microscopy (AFM).
• To assess the role of cellular components in governing friction.

Main Methods:

• Utilized an atomic force microscope (AFM) with a spherical probe (5 microm diameter) to simulate endovascular stent asperities.
• Characterized the surface frictional properties of VSMCs in contact with a metallic endovascular stent.
• Applied cellular crosslinking and cytoskeletal depolymerization agents to modify cell structure.

Main Results:

• The frictional coefficient of the AFM probe on VSMCs was determined to be approximately 0.06.
• Cellular crosslinking and cytoskeletal depolymerization significantly affected the measured frictional coefficient.
• Demonstrated that AFM-based lateral force microscopy can assess micro-scale friction of single cells.

Conclusions:

• AFM-based lateral force microscopy is a valuable tool for evaluating the friction properties of individual cells.
• Cellular structure, particularly the cytoskeleton, plays a significant role in determining friction.
• Findings contribute to understanding cell-surface interactions relevant to medical devices like stents.