���˾þ�

A thick, bite-sized piece of chicken fillet has been grown in a lab using tiny tubes to mimic the capillaries found in real muscle. Researchers say this gives the product a chewier texture.

When growing thick pieces of cultured meat, one major problem is that cells in the centre don’t get enough oxygen or nutrients, so they die and break down, says at the University of Tokyo.

“This leads to necrosis and makes it hard to grow meat with good texture and taste,” he says. “Our goal was to solve this by creating a way to feed cells evenly throughout the tissue, just like blood vessels do in the body. We thought, ‘What if we could create artificial capillaries using hollow fibres?’”

The fibres used by Takeuchi and his colleagues were inspired by similar hollow tubes used in the medical industry, such as for kidney dialysis. To create the lab-grown meat, the team essentially wanted to create an artificial circulatory system. “Dialysis fibres are used to filter waste from blood,” says Takeuchi. “Our fibres are designed to feed living cells.”

First, the researchers 3D-printed a small frame to hold and grow the cultured meat, attaching more than 1000 hollow fibres using a robotic tool. They then embedded this array into a gel containing living cells.

Free newsletter

Sign up to The Earth Edition

Unmissable news about our planet, delivered straight to your inbox each month.

Sign up to newsletter

“We created a ‘meat-growing device’ using our hollow-fibre array,” says Takeuchi. “We put living chicken cells and collagen gel around the fibres. Then we flowed nutrient-rich liquid inside the hollow fibres, just like blood flows through capillaries. Over several days, the cells grew and aligned into muscle tissue, forming a thick, steak-like structure.”

The resulting cultured chicken meat weighed 11 grams and was 2 centimetres thick. The tissue had muscle fibres aligned in one direction, which improves texture, says Takeuchi. “We also found that the centre of the meat stayed alive and healthy, unlike past methods, where the middle would die.”

Your ultimate guide to ultra-processed food – how bad is it really?

Highly processed foods, from pizza to bread, are said to be seriously bad for your health. Here is a digestible guide to what the evidence says, to help you make sense of the conflicting claims

While the meat wasn’t considered suitable for a human taste test, a machine analysis showed it had good chewiness and flavour markers, says Takeuchi.

Manipulating the hollow fibres may also make it possible to simulate different cuts of meat, he says. “By changing the fibre spacing, orientation or flow patterns, we may be able to mimic different textures, like more tender or more chewy meat.”

at the University of New South Wales in Sydney says that while it is impressive research, the process would be difficult to carry out on an industrial scale. “[The] holy grail in this whole field is scaling up of new technology,” he says.