MIT scientists have developed a groundbreaking method to grow artificial blood vessels, marking a significant advancement in the field of tissue engineering. This innovative approach involves using mechanical stretching to enhance the growth of new capillary-like sprouts and guide their direction. The research, published in the Proceedings of the National Academy of Sciences, introduces a vessel-on-a-chip platform that utilizes magnets to apply controlled strain inside a three-dimensional tissue model, offering unprecedented control over the growth and direction of blood vessels.
The device, smaller than a postage stamp, features a central hollow channel lined with human endothelial cells, which naturally form blood vessels. By embedding a magnetic actuator within a collagen gel, the researchers can stretch the vessel wall using an external magnet, adjusting the strength, frequency, and direction of the stretch. This mechanical stimulation promotes the formation of new blood vessels and influences their growth patterns.
One of the key findings is that dynamic stretching at 5% strain produced the largest number of sprouts, while 15% dynamic strain resulted in fewer sprouts but longer vessels. The direction of stretching also played a crucial role, with sprouts preferentially growing along the axis of actuation. This discovery allows researchers to precisely control the geometry and direction of blood vessel growth, a significant advancement in tissue engineering.
Furthermore, the study revealed that mechanical stimulation improved the barrier function of the vessel wall, reducing permeability to tracers. This finding suggests that the approach could enhance the structural integrity of artificial blood vessels. The researchers also identified PIEZO1, a gene that helps cells sense mechanical pressure, as a key player in strain-induced vessel growth. Suppressing PIEZO1 reduced the increase in sprouting but did not compromise the barrier function, indicating the presence of other force-sensing pathways.
The practical implications of this research are far-reaching. By precisely guiding small blood vessels, the magnetic platform can overcome a major barrier in tissue engineering, enabling the creation of fine networks with controlled geometry. This approach can be used to add physical instructions to growing tissues, allowing for the redirection of vessel growth through three dimensions. Future versions of the platform will incorporate additional cell types and flowing blood to better mimic native circulation, potentially leading to thicker and better-supplied implants.
In conclusion, MIT's innovative vessel-on-a-chip platform represents a significant leap forward in tissue engineering, offering a novel way to grow and guide artificial blood vessels. This breakthrough has the potential to revolutionize the field, enabling the creation of more realistic laboratory models for studying diseases and developing advanced implants.
