Endothelial Cells Increase Mesenchymal Stem Cell Differentiation in Scaffold-Free 3D Vascular Tissue

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Vascular tissue engineering aims to create functional blood vessel replacements.
• Scaffold-free methods offer advantages in mimicking native tissue complexity.
• Human mesenchymal stem cell-derived smooth muscle cells (hMSC-SMCs) and endothelial cells (ECs) are key components for vascular constructs.

Purpose of the Study:

• To develop a scaffold-free method for creating ring-shaped engineered vascular tissue segments.
• To investigate the effect of incorporating ECs on hMSC-SMC differentiation and tissue properties.
• To establish a functional 3D human vascular cell coculture model.

Main Methods:

• Co-seeding hMSCs and ECs at varying concentrations (0-30%) in ring-shaped agarose wells.
• Culturing engineered tissue rings in differentiation medium for 22 days.
• Assessing structural and functional properties via histology, Western blotting, wire myography, and tensile testing.

Main Results:

• Tissue rings with 20% and 30% ECs showed significantly increased SMC contractile protein expression and ET-1-mediated contraction.
• Higher EC concentrations (20% and 30%) led to enhanced force at failure compared to controls (0% ECs).
• Incorporation of 30% ECs into fused tissue-engineered blood vessels (TEBVs) increased SMC protein expression without compromising fusion.

Conclusions:

• Co-seeding hMSCs with ECs in a scaffold-free system promotes hMSC-SMC differentiation and enhances vascular tissue function.
• This approach yields stronger and more contractile engineered vascular tissues.
• The study presents a viable method for creating functional 3D human vascular cell coculture models for research and therapeutic applications.