surgeons hands using tools to stitch
Brittany Hambleton
Brittany Hambleton
February 2, 2024 ·  3 min read

Scientists Grow ‘Yarn’ From Human Flesh So They Can Stitch People Up, Repair Organs

There’s a good chance that you or someone you know has had to have stitches at some point in their life, whether because of an injury or as part of a surgical procedure. But have you ever stopped to ask yourself what those stitches are made of?

Stitches, or sutures, which is their medical term, can be made of a variety of materials depending on their purpose and placement, but soon your doctor may be able to stitch you up with yarn made from actual human skin.

Human Textile

Researchers at the French National Medical Institute of Health and Medical Research in Bordeaux have managed to create a “yarn” out of human skin cells that surgeons will be able to use to close wounds or put together implantable skin grafts [1,2].

“These human textiles offer a unique level of biocompatibility and represent a new generation of completely biological tissue-engineered products,” said the researchers [2].

Nicholas L’Heureux, who leads the team, explained that this new material can be used in a variety of ways for a number of different purposes.

We can sew pouches, create tubes, valves and perforated membranes,” he said. “With the yarn, any textile approach is feasible: knitting, braiding, weaving, even crocheting.” [3]

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What Material are Stitches Usually Made of?

Stitches can be made of a variety of materials, and your doctor will decide which type to use based on the physical and biological characteristics of the material in comparison to the healing process. There are two basic types of stitches, absorbable and non-absorbable [4].

Absorbable stitches are digested by tissue enzymes, and so will break down harmlessly in the body over time. For this reason, they do not need to be removed. Non-absorbable tissues, however, must be manually removed. Stitches that are to be used in a more stressful environment, like the heart or the bladder, require stronger, specialized materials that are usually non-absorbable to reduce the risk of degradation [4,5].

These are the types of materials normally used for stitches:

  • Absorbable: Polyglycolic Acid sutures, Polyglactin 910 , Catgut, Poliglecaprone 25 and Polydioxanone sutures.
  • Non-Absorbable: Polypropylene sutures, Nylon (polyamide), Polyester, PVDF, silk and stainless steel sutures [5].

Stitches may also be classified based on the structure of the material:

  • A monofilament suture is a single-stranded filament stitch. This type of suture has a lower risk of infection, but has poor knot security and is more difficult to handle.
  • A multifilament suture is made of several filaments that are woven together (such as in a braid). They are easier to handle and have better knot security, but they carry a greater risk for infection [6].

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Advantages of “Human Textile

The main advantage of using this new type of “yarn” is that, unlike the synthetic materials that are normally used, human skin cells do not trigger an immune response. This is important because an adverse immune response can cause inflammation and slow down the natural healing process [1,3].

The research is based on work that was done previously by the same team, in which they constructed blood vessels from human fibroblasts, which are the principal active cell in human connective tissue [7,8].

Early Success

So far, the researchers have successfully used the yarn to stitch up a rat’s wounds, which took two weeks to heal and created a skin graft to seal up a sheep’s leaky artery [1].

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  1. Scientists Grow ‘Yarn’ Out of Human Skin Cells So They Can Literally Stitch People Up.” Science Alert. Victor Tangermann. February 2020.
  2. Human textiles: A cell-synthesized yarn as a truly bio material for tissue engineering applications.” Science Direct. Laure Magnan, et al. March 15, 2020.
  3. Yarn grown from human skin cells could be knitted into your body.” New Scientist. James Urquhart. February 4, 2020.
  4. Suture Materials.” Elentra
  5. Types of Sutures | Suture Materials.” Dolphin Sutures
  6. Suture Materials.” Teach Me Surgery
  7. Human tissue-engineered blood vessels for adult arterial revascularization.” Nature. Nicolas L’Heureux, et al. February 2006.
  8. fibroblast.” Britannica