Strategies for improved endothelial cell adhesion in microphysiological vascular model systems

Area of Science:

• Biomedical Engineering
• Vascular Biology
• Tissue Engineering

Background:

• Tissue-engineered blood vessels (TEBVs) are crucial in vitro models for studying vascular diseases like atherosclerosis.
• Maintaining a functional, confluent endothelial monolayer in TEBVs under shear stress is a significant challenge.
• Current methods often struggle with consistent endothelial cell attachment and coverage.

Purpose of the Study:

• To develop and optimize a protocol for robust endothelialization of human TEBVs.
• To identify key factors influencing endothelial cell adherence and survival within engineered vessels.
• To enhance the reliability of TEBVs as disease models by ensuring endothelial integrity.

Main Methods:

• Optimization of endothelial cell (EC) seeding density, rotation time, and perfusion parameters.
• Redesign of TEBV chambers with integrated viewing windows for real-time monitoring.
• Assessment of EC coverage, alignment, and responsiveness to inflammatory stimuli using fluorescence microscopy.

Main Results:

• Achieved sustained and confluent endothelial cell luminal coverage in TEBVs.
• Demonstrated EC alignment with the direction of applied physiological shear stress.
• Confirmed EC responsiveness to inflammatory stimuli, indicating functional endothelium.
• Developed a streamlined monitoring system for efficient assessment of endothelialization.

Conclusions:

• The optimized protocol significantly improves endothelialization success in TEBVs.
• This method enhances the utility of TEBVs for in vitro vascular disease research.
• The redesigned chambers facilitate rapid assessment and fabrication of functional engineered vessels.