Human Endothelium-on-a-Chip: Development of a Microfluidic Model for Cell Viability Assessment Under Oxidative Injury

Area of Science:

• Biomedical Engineering
• Cell Biology
• Physiology

Background:

• Endothelial cells are crucial in vascular health and respond dynamically to mechanical forces like shear stress.
• Existing in vitro models often fail to replicate the complex interplay of blood flow, shear stress, and oxidative stress experienced by endothelial cells in vivo.
• Understanding these responses is vital for developing effective treatments for vascular diseases.

Purpose of the Study:

• To develop and validate an advanced endothelium-on-a-chip model that accurately mimics physiological blood flow and shear stress conditions.
• To investigate the impact of flow on endothelial cell sensitivity to acute oxidative injury.
• To assess the utility of this model for screening antioxidant compounds.

Main Methods:

• Development of an endothelium-on-a-chip system using EA.hy926 cells, adapted for non-CO2 environments and enhanced cell adhesion via collagen coating.
• Application of shear stress up to 0.89 Pa, simulating in vivo aortic and venous conditions.
• Design of an acute oxidative injury protocol using hydrogen peroxide (H2O2) and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH).

Main Results:

• The endothelium-on-a-chip model successfully maintained endothelial cells under physiological shear stress.
• Flow conditions significantly increased endothelial cell sensitivity to oxidative injury, evidenced by lower IC50 values for both H2O2 and AAPH compared to static conditions.
• Pretreatment with quercetin demonstrated a protective effect against AAPH-induced injury, validating the model's potential for antioxidant screening.

Conclusions:

• The developed endothelium-on-a-chip model provides a more physiologically relevant platform for studying endothelial responses to oxidative stress under flow.
• This model enhances the sensitivity to oxidative injury, offering a valuable tool for drug discovery and efficacy testing.
• The model's capacity to screen antioxidant compounds highlights its potential application in developing novel therapeutic strategies for vascular diseases.