We can stop the infection before it enters our bodies – if we mimic the texture of insect wings on the surface and start covering elevator buttons and door handles with materials that kill microbes or suppress their development.
Ten million deaths a year. The figure is incomprehensible, but it is one that Gerald Larua-Momu, an infectious disease researcher at Imperial College London (United Kingdom), often quotes. It will be a sad outcome for our world if all disease-causing microbes develop resistance to antibiotics, the main barrier we rely on to fight disease.
Today, 700,000 people die each year from diseases that have no medical treatment. And over the past 10 years, the list of drugs we can use against harmful bacteria has shrunk before our eyes. Meanwhile, other pathogens – fungi, viruses and parasites – have developed resistance to drugs at almost the same rate as we have developed new ones. This means that the diseases they cause are becoming increasingly difficult to treat.
As Larue-Momyu warned, “If nothing is done, 10 million people will die every year. He is one of the scientists looking for new ways to break the resistance of microbes. In Lyarua-Momyu’s plans, the same surfaces through which microorganisms are transmitted from person to person will be turned into antimicrobial weapons. “Surfaces that we touch every day are potential vehicles for the transmission of infections,” says Laru-Momyu. For example, the Sars CoV-2 virus, which causes Covid-19, can live on cardboard surfaces for up to 24 hours and on plastic and metal (stainless steel) for up to three days (although scientists debate the extent to which it retains its properties and infectivity. – Ed). And some bacteria, including E. coli and Staphylococcus aureus, can sometimes remain viable on the surfaces of inanimate objects for several months. This underscores the importance of constantly disinfecting and cleaning surfaces that we touch frequently.
Using antimicrobial metals or special coatings in the places we touch most reduces the risk of spreading infection. We explain quickly, simply, and clearly what happened, why it matters, and what happens next. The number of episodes should remain the same. End of story: Podcast Advertising
Some scientists hope to be able to destroy infectious microorganisms before they enter our bodies – simply by changing the texture of surfaces or coating them with a special layer that kills viruses and bacteria more quickly. Leroy-Merlin relies on copper alloys. Copper ions are both antibacterial and antiviral, capable of destroying more than 99.9% of bacteria in just two hours. Copper is even more effective than silver, which requires moisture to activate its antimicrobial properties. “Copper has been used by mankind for three thousand years,” Lyrau-Momyu points out. “Even the ancient Greeks made medical instruments and kitchen utensils from copper. Yet copper is rarely used in healthcare facilities today. It is an expensive metal that is difficult to clean without causing corrosion. And besides, not everyone wants a metal toilet seat… Over time, copper was replaced first by stainless steel, then by lightweight and inexpensive plastic, which Laroua-Momu says can be thrown away after use without worrying about sterilization. And while it is not possible to cover all surfaces with copper, Lyarua-Momy believes that using the metal in alloys in the “hot spots” that people touch all the time – elevator buttons, door handles, etc. – will be enough to limit the spread of germs. – will be enough to limit the spread of microbes and reduce infections. In addition, copper surfaces can be treated with a laser to create a rough texture that increases the surface area and thus the number of bacteria it can destroy. Researchers at Purdue University in Indiana, who developed the technology, found that such a surface is capable of killing even highly concentrated strains of antibiotic-resistant bacteria in just a few hours. And such processing will be useful not only for door handles, but also for medical implants, such as those used in hip replacements, to reduce the risk of infection.
There are other suggestions for changing the surface texture. ” Cicada wings have self-cleaning properties,” says Elena Ivanova, a molecular biochemist at the Royal Melbourne Institute of Technology (Australia). Their wings have hydrophobic properties, so water droplets roll off them like lotus leaves, along with pollutants. More importantly, she says, cicadas’ wings are covered with tiny spines that prevent bacterial colonization of the surface. “This is a unique mechanism created by nature to destroy bacterial cells,” explains Ivanova, who has developed nearly ten ways to mimic the structure of a cicada’s wing device.
Hospitals are finding it increasingly difficult to control bacteria that have become resistant to antibiotics. The saturation, geometric characteristics, method and materials used to create such a surface depend on the specific microorganisms to be controlled. According to Ivanova, the complex zigzag texture is particularly effective in water and air filters. Graphene sheets are very thin, with sharp protrusions that cut through bacterial membranes and kill them (although these microscopic razors can also damage human skin). Ivanova is particularly excited about the possibility of using titanium and titanium alloys. They can be hydrothermally processed under high temperature and pressure, so that a thin sheet of metal is left with sharp protrusions and edges that destroy various types of bacteria. In addition, when titanium dioxide is exposed to ultraviolet radiation, it forms active forms of oxygen, such as peroxides, which inactivate (block) microorganisms. This is already used, for example, in coatings for dental braces. “Such surfaces do not require any special treatment,” Ivanova points out. However, the production of these surfaces requires a high degree of precision, since their elements are smaller than bacteria. According to Vladimir Baulin, a biophysicist at Rovira i Virgili University (Spain), similar technologies can be used against viruses, including coronaviruses. One possible strategy is to trap viral particles between artificially created nanocomponents on the surface. This will help scientists collect viral particles for research and vaccine development. Another strategy is to create a texture on the surface with sharp protrusions that can physically pierce the outer membrane of the virus cell. Such a surface could be used in mask filters, for example.
Nature itself offers us a variety of ways to combat the spread of infectious diseases. “There is a lot of evidence for the effectiveness of essential oils as antibacterial and antiviral ingredients,” says Alejandra Ponce, a chemical engineer at the National University of Mar del Plata (Argentina). Take, for example, tea tree oil, a strong-smelling ingredient in many cosmetic products. As Ponce notes, experimental studies have shown that tea tree oil aerosol has a strong antiviral effect and can block viral samples with an efficiency of more than 95% in just 5-15 minutes of exposure. Cork has proven to be a highly effective antibacterial material against golden staph. And hop extracts have been used to create a plastic-like coating that prevents the growth of certain types of bacteria on surfaces. Similar research is currently in the experimental stage. In theory, these natural materials could be turned into antimicrobial coatings, but much remains to be learned about the exact amount of key ingredients and the type of microorganisms these coatings will target.
If we manage to copy the features of the cicada’s wing structure, such a surface will help fight the formation of bacterial colonies. But in general, the range of potential applications for antimicrobial surfaces is quite broad. “I think it is important to emphasize that this is a universal mechanism, and that is why the scope of its application is so wide,” says Baulin. However, it is not advisable to rely too heavily on this approach, warns Mengin Ren, who works with the Swedish network ReAct – Action on Antibiotic Resistance. As she points out, no matter how good the technology, it is still necessary to meet the basic requirements for medical facilities – qualified staff, sanitation, hygiene, infectious disease prevention and control, and vaccination. There are no easy solutions. In poor countries, where reliable access to running water is not always available, it is especially difficult to keep surfaces that require frequent treatment clean. However, according to Ivanova, titanium and titanium alloys are self-cleaning of pathogenic cells. And as for copper surfaces, they need to be cleaned to limit oxidation, which makes this metal less chemically active. Ren and her colleagues are concerned about the risk of pathogenic microorganisms developing resistance to copper with silver or to new antibacterial surfaces. But Laroche-Momay is confident: “If bacteria have not developed resistance to copper in the last 3,000 years, it is unlikely that they will do so in the future.
Cork has antimicrobial properties, so cork floors are not only good for sound insulation and comfort. Either way, it will take time for these technologies to find commercial developers and move to the stage of widespread adoption. However, there are already several examples. Sharklet (not to be confused with aeronautical sharklets – wing tips that improve aerodynamics – ed.) is a plastic film material that imitates shark scales. Its surface consists of rhomboids with sharp, tooth-like scales that repel all foreign substances, including bacteria. This material is already used in medical applications, such as catheters, where it is particularly important to reduce the risk of infection entering the body. MicroShield 360 is also available, which is applied to airplane seats to prevent the buildup of bacteria. And while 3D printers rarely work at the nanoscale, some models can. One day, it will be possible to print a micro-DNA-repellent surface right in your own home. Such surfaces could become an important tool in the future fight against infectious diseases and pandemics.
Already today, as the world battles the Covid-19 virus, the issue of antimicrobial resistance is of paramount importance. Therefore, there is a significant risk of secondary infections that a patient may contract in the hospital: one study showed that 50% of patients who died from Covid-19 in a Chinese hospital were also infected with another (potentially lethal) pathogen. Those infected with the coronavirus are usually given antibiotics (although they have no effect on the virus itself). This raises concerns about further increases in bacterial resistance to drugs. “We are surrounded by infections, so there is nothing unusual about our current war with the coronavirus,” Lyauro-Momyu emphasizes. “And now it is very important to prepare for the next one. It is unknown when it will begin.”
I’m sorry, but there is no text provided to translate from Russian to English. Could you please provide the Russian text? You can read the original article on the BBC Future website.