You probably won’t want your holiday sweater knitted with it, but yarn grown from human skin cells could nonetheless be a crucially important invention for future tissue grafts and organ repairs. The “human textiles” have been developed by researchers at the French National Institute of Health and Medical Research. Unlike synthetic materials which are currently used for things like sutures or scaffolds for growing tissues, skin cell yarn won’t provoke an immune system reaction that can cause inflammation in patients. Instead, they could seamlessly be woven into hosts without risk of rejection.
“We start with normal adult human cells that are grown in the lab, at the bottom of a special plastic container,” Nicholas L’Heureux, the researcher who led the work, told Digital Trends. “On that plastic, the cells will synthesize and assemble what is called an ‘extracellular matrix’ or ECM. The ECM is the basic scaffolding of practically every organ in the body. The most abundant, and best know, part of the ECM is a protein called collagen. In the right conditions, the cells will deposit a layer of ECM at the bottom of the container as a continuous sheet.”
The scientists then take this sheet — or “cell-assembled matrix” (CAM) — and cut it into ribbons of just a few millimeters width. These can be used directly as yarn or twisted into special threads with subtly different mechanical properties. The process allows the researchers to produce textiles that can be used for any of the well-known assembly approaches of the textile industry, including weaving, knitting, and braiding. In a recent proof-of-concept demonstration, the researchers used the skin-based yarn to stitch closed a wound on a rat.
“Our main goal is to produce a vascular graft made by weaving the CAM yarn,” L’Heureux continued. “We are currently building prototypes and learning more about the handling of that new material. We will soon start testing these grafts in animals so that we can eventually move to human trials for patients who need heart bypass, leg bypass, or a vascular graft for hemodialysis.”
While this work may not be quite ready for prime time just yet, related work by L’Heureux is already being used to help people. For instance, he has used his skin cell-based sheets to create a scaffold for lab-grown skin that is today being used on burn patients. It is also being utilized by L’Heureux’s colleagues to create nerve guides to repair nerve injuries, while investigations are underway for other use cases such as its use in heart valve prototypes and lab-grown ligaments for orthopedic repair.
A paper describing the work was recently published in the journal Acta Biomaterialia.