Microtopography and flow modulate the direction of endothelial cell migration

Area of Science:

• Biomaterials Science
• Cell Biology
• Bioengineering

Background:

• Endothelial cell migration is crucial for vascular health.
• Cell migration is influenced by physical cues like fluid shear stress and substrate topography.
• Understanding these interactions is key for tissue engineering and regenerative medicine.

Purpose of the Study:

• To investigate the combined effects of substrate microgroove topography and fluid shear stress on endothelial cell migration.
• To determine how microgroove dimensions and orientation influence cell behavior under varying flow conditions.

Main Methods:

• Bovine aortic endothelial cells were cultured on poly(dimethylsiloxane) substrates with microgrooves (2-5 µm width, 1 µm depth).
• Cells were observed using time-lapse microscopy under varying fluid shear stress conditions (0, 13.5, and 58 dyn/cm²).
• Focal adhesions and actin microfilaments were analyzed to assess cytoskeletal organization.

Main Results:

• In the absence of flow, cells migrated parallel to microgrooves, with focal adhesion distribution dependent on groove width.
• Moderate shear stress did not alter the migratory pattern.
• High shear stress caused cells to migrate downstream with flow, but cytoskeletal and focal adhesion alignment initially remained parallel to the grooves.

Conclusions:

• Substrate topography plays a significant role in directing endothelial cell migration.
• Under high shear stress, topographic cues remain dominant in guiding cytoskeletal and focal adhesion orientation initially.
• These findings have implications for designing biomaterials that control cell behavior in vascular applications.