Human textiles for tissue repairs

The extracellular matrix produced by human cells has been fashioned into a yarn and weaved to make new blood vessels

Original source: Materials Today

‘Yarn’ made from human tissue can be woven like a textile and could be used to help repair bodily injuries. A research team based in France is developing the material, for which the potential applications range from simple biocompatible sutures to complex woven tissues for surgical repairs.

The researchers report on their innovation and proof-of-concept creation of blood vessels in the journal Acta Biomaterialia. “Our strategy is much faster, cheaper, and more versatile than our previously described approaches,” says research group leader Nicolas L’Heureux of the University of Bordeaux.

L’Heureux and his colleagues have been working to get human cells to make tissues for body repairs for many years. “I began during my PhD studies in Quebec in the mid-1990s,” he says, emphasising that most scientific innovations develop slowly through decades of work.

He previously founded a start-up company in California – Cytograft Tissue Engineering – which was in operation for 15 years and claimed to be the first company to implant a tissue engineered blood vessel under arterial pressure. On moving his research to the BIOTIS Laboratory, linked with the University of Bordeaux, L’Heureux has been able to develop the more sophisticated concept of weaving tissue yarns.

The materials L’Heureux has spent such a long time working on are various forms of cell-assembled matrix (CAM), which human cells can be induced to grow into useful structures.

Scientists have been able to grow some tissues in the lab for years, with the best-known use being lab-grown skin for treating burns, but a major hurdle has been to create completely natural strong tissues, without having to use a synthetic scaffold. Avoiding anything synthetic offers the great advantage of biocompatibility, reducing the chance of any repair being attacked as foreign and rejected.

L’Heureux and his colleagues have now shown that sheets of CAM can be used to make a strong yarn by cutting the sheet into ribbons which, if desired, can then be twisted into threads.

“The yarn, whether in the form of ribbons or threads, can be made into practically any shape by weaving, braiding, or knitting,” says L’Heureux. He points out that taking this textile-like approach offers excellent control over the mechanical properties of whatever product the yarn is weaved into. The assembly of the material can also be automated, much like weaving cloth, to make production faster, easier and cheaper than previous approaches based on sheets of CAM.

In their current article the researchers demonstrate that their yarn can be fabricated into artificial blood vessels, in addition to being used as sutures to close wounds. They next plan to demonstrate its use more fully in animal models, and also to explore making a wider range of tissues. Targets include making replacement ligaments, heart valves and oesophagi, while also using the yarn to support weakened tissues that might then not need to be fully replaced. L’Heureux hopes this work can soon move onto the crucial phase of clinical trials.

Article details:

L’Heureux, N. et al.: “Human textiles: A cell-synthesized yarn as a truly “bio” material for tissue engineering applications,” Acta Biomaterialia, 2020