Scientists hope to one day replace damaged body parts with lab-made alternatives, but recreating complex tissues and organs remains challenging. Blood vessel networks are particularly difficult to reproduce because tiny capillaries can be microscopic, with some measuring just 0.005 millimeters wide and allowing blood cells to pass through one at a time.
MIT Creates More Precise Artificial Blood Vessels
A team of MIT researchers has published a study in PNAS describing a new method for creating artificial blood vessels in the lab with improved accuracy. Developing functional blood vessels is essential for engineered tissues and organs because capillaries deliver oxygen and nutrients through the body.
The new technique uses magnetic forces to carefully guide and align blood vessel cells as they grow.
According to MIT mechanical engineer Ritu Raman, current methods cannot reliably create the organized vascular networks needed for healthy engineered tissues. She explained that controlling blood vessel development through physical signals could make it possible to produce larger, more consistent lab-grown tissues for implantation, helping restore body functions damaged by disease or injury.
The system uses a small chip containing lab-grown endothelial cells, which form the inner lining of blood vessels, embedded in a collagen gel — a key structural protein in the human body.
A tiny magnet inside the chip was manipulated by external magnets from different directions, allowing researchers to control the forces applied and guide the growth of new blood vessels.
Magnetic Control Guides Artificial Vessel Growth
The method builds on a technique the team previously developed for producing artificial muscles and nerves. By adjusting the strength of the magnetic force, scientists could regulate the size and number of newly formed vessels. Although still in the early prototype phase, the results show promising potential.
Raman explained that the key finding is that repeatedly stretching blood vessels appears to increase the growth of new capillaries. She added that mechanical forces influence how blood vessels develop, meaning scientists may now have a way to control their number, length, and direction.
The creation of new blood vessels, known as angiogenesis, has been difficult to replicate in the laboratory with enough accuracy. While researchers can already 3D-print vessels or grow them from individual cells in nutrient-rich dishes, these approaches still lack the level of control needed for more advanced tissue engineering.
Physical Cues Improve Control Over Blood Vessel Growth
Raman explained that chemical signals, such as growth factors, can influence blood vessel formation, but they do not offer enough precision to control where vessels develop. She noted that additional physical cues are needed to create tissues with properly organized vascular networks.
The researchers also studied the biological processes behind this effect by repeating the experiments with cells modified to lack the PIEZO1 gene. This gene regulates ion channels that act like cellular gateways, controlling the movement of substances in and out of cells and responding to mechanical forces. When PIEZO1 was inactive, fewer blood vessels formed, suggesting that these mechanically sensitive channels play a key role in vessel growth.
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