New Tooth Engineered Coating Stronger Than Enamel

Calendar September 22, 2022 | Posted by admin

Scientists in Russia  have perfected hydroxyapatite, a material for mineralizing bones and teeth. By adding a complex of amino acids to hydroxyapatite, they were able to form a dental coating that replicates the composition and microstructure of natural enamel. Improved composition of the material repeats the features of the surface of the tooth at the molecular and structural level, and in terms of strength surpasses the natural tissue. The new method of dental restoration can be used to reduce the sensitivity of teeth in case of abrasion of enamel or to restore it after erosion or improper diet.
Hydroxyapatite is a compound that is a major component of human bones and teeth. Scientists selected a complex of polyfunctional organic and polar amino acids, including, for example, lysine, arginine, and histidine, which are important for the formation and repair of bone and muscle structures. The chosen amino acids made it possible to obtain hydroxyapatite, which is morphologically completely similar to apatite (the main component of tissues) of dental enamel. The researchers also described the conditions of the environment in which the processes of binding of hydroxyapatite to the dental tissue should occur. Only if these conditions are met it is possible to fully reproduce the structure of natural enamel.

“Traditionally in dentistry, composite restorative materials are used in enamel restoration. To increase the bonding efficiency of enamel and composite, the restoration technique involves acid etching of the enamel beforehand. The etching products left behind may not always have a positive effect on the bonding of enamel and synthetic materials. To reproduce the enamel layers with biomimetic techniques, we neutralized the media and removed the etching products using calcium alkali. In this way we improved the binding of the new hydroxyapatite layers,” explains Pavel Seredin.
The formation of a mineralized layer with properties resembling those of natural hard tissue was confirmed by field emission electron and atomic force microscopy as well as by chemical imaging of surface areas using Raman microspectroscopy. The study was conducted on healthy teeth to eliminate the influence of extraneous factors on the resulting layer and to be able to compare the results with healthy teeth. Next, the researchers will tackle the challenge of repairing larger defects, which can be of varying nature from the initial stages of caries to cracks and volumetric fractures.

The joint research was conducted by scientists from the Research and Education Center “Nanomaterials and Nanotechnologies” of Ural Federal University, Voronezh State University, Voronezh State Medical University, Al-Azhar University, and the National Research Center (Egypt).

The study and experimental results are published in Results in Engineering.

Source: https://urfu.ru/

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Robots With Living Human Skin

Calendar June 20, 2022 | Posted by admin

Shoji Takeuchi and colleagues from the Department of Mechano-Informatics and the Graduate School of Information Science and Technology at the University of Tokyo have developed a method for coating a robotic finger with living human skin. Their findings were published in the journal Matter. Scientists believe a new class of skin-covered robots could more effectively interact with their human counterparts.

“There are three benefits to using living cells as a coating material for robots. First, by using the same skin material as humans, a more human-like appearance can be achieved. Second, the biological properties of cells can be used to provide robot skin with multimodal and multichannel sensing capabilities, self-repair capabilities, and metabolic capabilities that are difficult to achieve with artificial materials alone. Third, by using biological materials, robots can be made more environmentally friendly,” Takeuchi told Syfy Wire.

To get the skin onto the robotic appendage, scientists submerged it in a combination of collagen and human skin cells. Over time, the mixture attached itself to the finger, creating a first layer of skin. A second liquid containing keratinocyte cells — the dominant cells found in the epidermis — was then applied creating an outer layer. After a couple of weeks, the robotic finger had skin which was comparable in width to our own. Previous studies grew skin-like structures separately and later applied them to a synthetic surface. This new strategy has benefits over previous methods, in that it allows for the application of skin over uneven surfaces.

“We found that we could adapt the skin to the curved 3D surface shape by culturing it on site, rather than making it elsewhere and attaching it to the surface. By installing an appropriate anchor structure, the entire surface could be covered,” Takeuchi said.

At present, the skin does not deliver any sensory information to the robot, but the team is working on incorporating a nervous system for just that purpose. The skin also doesn’t include any circulatory system for delivering nutrients to the tissue. As a result, it needed external assistance to acquire nutrients and for the removal of waste products. That means it spent a considerable portion of its time in a bath of sugars and amino acids.

“We are conceiving strategies to build circulatory systems within the skin. Another challenge is to develop more sophisticated skin with skin-specific functions by reproducing various organs in the skin such as sensory neurons, hair follicles, nails, and sweat glands,” Takeuchi explained.

That’s not to say the skin isn’t impressive even as it exists today. The current version was able to stretch with the finger as it bent or straightened and even healed itself after injury. Researchers made a small cut on the surface of the finger and then applied a collagen bandage. The cells of the skin then connected to the bandage and incorporated it into the skin, healing the wound.

Of course, the process will need to be scaled up if researchers hope to cover an entire humanoid robot in convincing human skin. A robot with disconnected pieces of skin might be even more terrifying to its human acquaintances than one with no skin at all. Now, that would be a dystopian nightmare better left to our fictions.

Source: https://www.u-tokyo.ac.jp/

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How To Eradicate (Again) Tuberculosis

Calendar July 30, 2020 | Posted by admin

Scientists find new way to kill tuberculosis (TB). A toxin called MenT can block the use of important amino acids required by the bacteria to produce essential proteins needed for survival. An international team of researchers, led by Durham University, UK, and the Laboratory of Molecular Microbiology and Genetics/Centre Integrative Biology in Toulouse, France, are aiming to exploit this  to develop new anti-TB drugs.

Surface electrostatic representation of toxin MenT (blue, positive; red, negative), showing where target tRNA would bind and the enzymatic active site.

TB is the world’s deadliest infectious disease with nearly 1.5 million deaths each year. Whilst most cases can be cured with , the number of antibiotic-resistant infections are steadily increasing. It is spread by breathing in tiny droplets from the coughs or sneezes of an infected person and mainly affects the lungs though it can affect any part of the body, including the glands, bones and  .

Bacteria, such as the germs that cause TB, produce toxins to help them adapt to stress in the environment. These toxins are normally counteracted by a matching antidote, but when they are active they can potentially slow bacterial growth and even lead to cell death. The research team found a new toxin, called MenT, produced by the TB bacterium Mycobacterium tuberculosis. The researchers built an extremely detailed 3-D picture of MenT which, combined with genetic and biochemical data, showed that the toxin inhibits the use of amino acids needed by the bacteria to produce protein.

If it is not neutralised by its MenA anti-toxin, MenT stalls the growth of Mycobacterium tuberculosis, causing the bacteria to die.

Co-Senior author Dr. Tim Blower, Associate Professor in the Department of Biosciences, and Lister Institute Prize Fellow at Durham University, said: “Effectively the tuberculosis is actively poisoning itself. “Through the forced activation of MenT, or by destabilising the relationship between the toxin and its anti-toxin MenA, we could kill the  that cause TB”  The remarkable anti-bacterial properties of such toxins make them of huge therapeutic interest.”

Their findings are published in the journal Science Advances.

Source: https://www.dur.ac.uk/
AND
https://phys.org/

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Molecular Baskets Swallow, Trap And Remove Toxic Compounds

Calendar October 11, 2018 | Posted by admin

Researchers have developed designer molecules that may one day be able to seek out and trap deadly nerve agents and other toxic compounds in the environment – and possibly in humans.

The scientists, led by organic chemists from The Ohio State University, call these new particles “molecular baskets.” As the name implies, these molecules are shaped like baskets and research in the lab has shown they can find simulated nerve agents, swallow them in their cavities and trap them for safe removal.

In a new study published in Chemistry – A European Journal, the researchers took the first step in creating versions that could have potential for use in medicine.

“Our goal is to develop nanoparticles that can trap toxic compounds not only in the environment, but also from the human body,” said Jovica Badjić, leader of the project and professor of chemistry and biochemistry at Ohio State.

The research focuses on nerve agents, sometimes called nerve gas, which are deadly chemical poisons that have been used in warfare.

In a study published last year in the Journal of the American Chemical Society, Badjić and his colleagues created molecular baskets with amino acids around the rims. These amino acids helped find simulated nerve agents in a liquid environment and direct them into the basket.

Source:  https://news.osu.edu/

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Nanoparticles Fom Tea Leaves Destroy 80% Of Lung Cancer Cells

Calendar May 23, 2018 | Posted by admin

Nanoparticles derived from tea leaves inhibit the growth of lung cancer cells, destroying up to 80% of them, new research by a joint Swansea University (UK) and Indian team has shown. The team made the discovery while they were testing out a new method of producing a type of nanoparticle called quantum dots.  These are tiny particles which measure less than 10 nanometres.  A human hair is 40,000 nanometres thick.

Although nanoparticles are already used in healthcare, quantum dots have only recently attracted researchers’ attention.  Already they are showing promise for use in different applications, from computers and solar cells to tumour imaging and treating cancer. Quantum dots can be made chemically, but this is complicated and expensive and has toxic side effects.  The Swansea-led research team were therefore exploring a non-toxic plant-based alternative method of producing the dots, using tea leaf extract.

Tea leaves contain a wide variety of compounds, including polyphenols, amino acids, vitamins and antioxidants.   The researchers mixed tea leaf extract with cadmium sulphate (CdSO4) and sodium sulphide (Na2S) and allowed the solution to incubate, a process which causes quantum dots to form.   They then applied the dots to lung cancer cells. Tea leaves are a simpler, cheaper and less toxic method of producing quantum dots, compared with using chemicals, confirming the results of other research in the field. Quantum dots produced from tea leaves inhibit the growth of lung cancer cells.  They penetrated into the nanopores of the cancer cells and destroyed up to 80% of them.  This was a brand new finding, and came as a surprise to the team.

The research, published in “Applied Nano Materials”, is a collaborative venture between Swansea University experts and colleagues from two Indian universities.

Source: http://www.swansea.ac.uk/

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