Artificial leather instead of natural
Leatherette
Ksenia Skrypnik, Copper News
Artificial skin that could be transplanted – that is, used to restore the integrity of the skin – would make the treatment of burns, ulcers and other large-scale injuries simpler, painless and effective. The idea of replacing real skin with a material grown in the laboratory seems quite attractive to researchers – this would avoid serious complications and speed up the healing process.
An artificial material that can be simply applied to the site of damage, like a patch, was invented by a team of Japanese scientists from Saga University. A special coating based on atelocollagen is intended for the treatment of burns. Atelocollagen is low-allergic and practically does not cause side effects.
Its effect was tested on laboratory mice – the new material really accelerated healing.
However, it can only be used as a temporary measure until the patient's skin becomes suitable for further transplantation, explains Toshiaki Takezawa. Clinical use of the new material will begin no earlier than 2022, the authors say.
Serpentine made of siliconIn the meantime, some scientists are inventing artificial leather that will not be rejected, while others are working on other materials.
The new coatings for prosthetic limbs are so perfect that they are able to "feel" the texture of surfaces and "feel" touches.
One of these developments was reported by Korean and American scientists at the end of 2014. They created a polymer material covered with a network of sensors made of silicon and gold – 400 pieces per 1 square millimeter. To make the "skin" elastic, silicon was given the shape of a serpentine.
Rozbeh Ghaffari from Cambridge noted that the elasticity of living skin and its sensitivity differ in different parts of the hand. The new material has the same properties: the number of sensors on the fingertips is much higher than on the back of the palm. To make the coating even more similar to the present, the authors added a special layer that warms the material to the temperature of the human body.
Testing artificial skin, Dae-Hyeong Kim and his colleagues from Seoul National University connected it to the brain of rats. The sensory cortex of the animals reacted to touch, but it was not possible to find out whether the animals distinguished heat, moisture or pressure. The researchers hope to find the answer after conducting experiments on larger animals.
A light touch and a firm handshakeOther research groups are also engaged in the creation of artificial skin for prosthetic limbs.
Zhenan Bao and her colleagues have developed a very advanced material.
The coating they created was called Di Tact. It consists of two layers. The upper one is covered with highly sensitive sensors that can "feel" and distinguish between a light touch and a handshake. And the lower layer is responsible for transmitting an electrical signal and converting it into a biochemical signal perceived by neurons.
In their experiments on laboratory mice, the authors clearly demonstrated that neurons in the brain of animals reacted to touch. Scientists explain that for the first time they managed to abandon the use of a device that converts a signal coming from a sensor into an impulse perceived by the brain.
Artificial skin was able to independently perceive, transform and transmit a signal from sensors to brain neurons. However, even this material is far from the properties of human skin – sensors are still unable to distinguish temperature, and sensitivity is far from ideal.
FingerprintsBy the way, a material capable of "feeling" temperature changes has already been created.
South Korean scientists from the National Institute of Science and Technology (National Institute of Science and Technology) succeeded in this. Their artificial skin is even more similar to the natural one – the authors have given it a special wavy structure characteristic of real skin. So, a pattern of "prints" appeared on the fingertips covered with a new material, and the ability to touch became even more perfect.
At any pressure on the material, its constituent layers are compressed, which creates an electric current, the strength of which is directly related to the degree of deformation of the skin: the stronger the pressure, the stronger the current will be. Artificial leather changes its properties when the temperature changes – it expands and softens when heated and becomes more rigid when cooled. Such changes also generate an electric current of varying strength.
Hyunhyub Ko and his colleagues explain that artificial leather has another unique feature – it is able to recognize sound waves. It turned out that sound also causes deformation of the layers of the new material, which leads to the generation of electrical impulses. However, scientists have not yet developed a way to transmit the generated impulses to the brain.
Some coatings used to accelerate wound healing have already been tested on patients and are likely to be used in clinical practice soon. But it is premature to talk about the beginning of the use of new coatings for prostheses with sensitivity. None of these materials has yet been tested on humans, however, scientists have no doubt that "tactile" prostheses will actually appear. It's only a matter of time.
Portal "Eternal youth" http://vechnayamolodost.ru
09.11.2015