Microfabricated blood vessels undergo neoangiogenesis

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Tissue engineering aims to create functional human organs, but a major hurdle is the lack of operational vasculature.
• Current limitations in manufacturing blood vessels hinder the growth and complexity of engineered tissues.

Purpose of the Study:

• To fabricate free-standing, small-diameter blood vessels with organized cell layers using microfluidic technology.
• To demonstrate the biological functionality and potential for vascularization of engineered tissues.

Main Methods:

• Utilized microfluidic technology with ultraviolet (UV) photo-crosslinkable poly(ethylene glycol) and gelatin methacrylate polymers.
• Integrated microfabricated vessels into three-dimensional gels containing fibroblasts to observe angiogenesis and network formation.
• Assessed vessel functionality through fluid and particle perfusion, response to stimuli, and cryogenic storage.

Main Results:

• Successfully fabricated small-diameter blood vessels with organized endothelial cell layers that remodeled the scaffold with extracellular matrix proteins.
• Observed microvessels sprouting, forming extended hollow branches, and anastomosing with neighboring capillaries to create a functional network.
• Demonstrated that both the microfabricated vessels and sprouts supported perfusion and mimicked native human blood vessels in response to stimuli.

Conclusions:

• Microfluidic fabrication of cellularized microvessels provides a scalable solution for vascularizing engineered tissues.
• These engineered blood vessels can be designed, produced, and matured to support organ repair and advanced drug screening platforms.
• The developed technology represents a significant advancement towards the goal of manufacturing 'made-to-measure' human tissues and organs.