The hi-tech 'printer' that makes sheets of skin to treat burns and repair big areas of damaged skin

A machine that produces large sheets of new skin for grafting could transform the treatment of patients who have severe burns.

The denovoCast can grow patches the size of a dinner plate, which are then used to repair large areas of damaged skin.

The grafts are made using a postage stamp-sized patch of the patient’s own healthy skin, taken from an undamaged area.

From this, doctors extract stem cells (‘master’ cells that can develop into healthy new tissue), collagen (the fibrous substance that gives skin its elasticity) and keratinocytes (cells that make skin waterproof and stop bacteria from entering it).

Once in the lab, a water-based gel is added and then the mixture is fed into the machine with growth factors, natural substances found in the body that stimulate new cell growth.

Over the next four weeks or so, the mixture grows into large, gel-like sheets of skin up to 100 times bigger than the harvested area. This is then grafted on to the patient’s burns.

About 130,000 people a year in England need emergency treatment for burns.

Although most can be treated with dressings, some 10,000 have to be admitted to hospital for treatment, including skin grafts. These are currently carried out by harvesting an inch or two of skin from an undamaged area.

This is then put through a mesher, a device that makes tiny slits in the graft so it can be stretched into a bigger piece that can cover larger damaged areas, where it is sutured into place.

But the technique only stretches skin to up to ten times its original size. This can mean having to harvest several healthy patches of skin to produce numerous grafts for large damaged areas. This can be a problem when patients have little healthy skin left.

In addition, conventional skin grafts only use the epidermis — the top layer of skin — because taking more than this would do too much damage.

But in major burns, the dermis — the inner layer of skin housing connective tissue, blood vessels, nerves and sweat glands — is also damaged. It then becomes scarred and the damaged tissue underneath the graft can contract, causing pain and restricting movement.

The new man-made skin — which has been in development for more than a decade and is currently in clinical trials at various centres around Europe — has fresh dermis tissue, as well as epidermis.

The process of making it has been slow and labour-intensive, with laboratory staff having to nurture the growth of each new sheet manually in large dishes.

However, the new denovoCast machine ‘industrialises’ the process, as it is programmed to grow numerous grafts at the same time and does so 30 per cent more quickly than by hand.

This is important because major burns victims can succumb to infection that gets in through the damaged skin, or loss of fluid that escapes from it, while waiting for a graft to be prepared.

Trial results are due in the next year or so but the treatment is already being used in a few cases of traumatic burns — including at least one case in the UK — on compassionate grounds.

David Barnes, a surgeon at St Andrew’s Centre for Plastic Surgery and Burns at Broomfield Hospital in Chelmsford, Essex, said: ‘This treatment looks very promising. One of the problems with current grafts is they can be quite unstable and easily break down. This seems to be much more robust.’

Didgeridoo for snoring children 

Learning to play a didgeridoo might help children who snore, suggest researchers from the Hôpitaux de Paris in France, who are trialling this as a treatment for sleep apnoea — where the soft tissues in the throat collapse, causing a temporary halt in breathing at night.

In the study, 74 children with the condition will be taught circular breathing — breathing in through the nose, then expelling air out of the mouth — which is key to creating the sound.

The technique, which is different to that used for contemporary wind instruments, has been shown to help adults with sleep apnoea, possibly because it strengthens throat muscles.

Using light to boost hearing

An implant that uses infrared light to boost hearing is about to undergo its first human tests.

The device, which is surgically implanted in the ear, stimulates hearing nerves with blasts of light. Hearing loss can occur when hair cells, which relay sound signals via nerves to the brain, become damaged either through injury, illness or defects at birth.

Cochlear implants can stimulate these nerves with electricity, but animal studies have found that light can target the nerves more precisely, allowing more information to be transmitted.

The new implant is being tested at Northwestern University, in the U.S., on 30 people with hearing loss.

Bee venom lets drugs into brain

The protein found in bee venom could be used to deliver vital drugs to the brain.

The blood-brain barrier, a wall made up of cells similar to those that line the blood vessels, stops harmful substances entering the brain, but also blocks almost all medication.

In experiments on mice, scientists at Johns Hopkins University in the U.S. showed that melittin — the bee venom protein — can temporarily ‘unlock’ small parts of the barrier.

This discovery means that it may be possible to engineer the protein so it can safely ferry drugs into the human brain, says the journal Biomaterials.

Do this

Avoid sharing food if watching your weight. A team at Ryerson University, Canada, found that when people shared chips with a friend, they thought the food was less fattening than if they had their own portion.