from the world's big
Smart bandages quickly identify antibiotic-resistant bacteria, and normal bacteria, in owies.
- Judicious use of drugs for resistant bacteria requires time- and money-consuming tests until now.
- New smart bandages turn red for resistant bacteria and yellow for antibiotic-sensitive bacteria.
- The bandages also promote healing with the application of UV light.
The growing incidence of antibiotic-resistant bacteria was already a worrying problem before we all started washing our hands with anti-bacterial soaps in response to SARS-CoV-2. While necessary, we may also have provided even more bacteria the opportunity to develop resistance. Such uncooperative bacteria can often be treated, but before they can, they have to first be identified as antibiotic-resistant — each time the precious meds capable of defeating such bacteria are deployed, we risk bacteria developing resistance to them. This would obviously render them useless, and so they're administered only sparingly to bacteria that have tested as resistant. This testing takes time, and can be expensive.
Researchers at the Chinese Academy of Sciences, Changchun, Jilin province have a better idea: smart bandages that change color to indicate the nature of bacteria they cover. The study describing their research his published in ACS Central Science.
The idea behind the bandages
Image source: Alex Kondratiev/Unsplash
The smart coverings work by leveraging the chemistry of bacterial infections. Integrated into each covering is a metal organic framework (MOF), a structure that allows scientists to embed a few key chemicals in the bandages.
The bandages contain a chemical called nitrocefin that breaks down in the presence of the enzyme β-lactamase — β-lactamase is the enzyme that resistant bacteria produce and use to neutralize antibiotics. It's essentially the chemical source of antibiotic resistance. When the nitrocefin interacts with β-lactamase, it breaks down and turns red — as does the bandage— signifying the presence of an antibiotic-resistant bacteria.
For detecting normal, antibiotic-sensitive bacteria, the bandages leverage the fact that a bacterial infection on your skin causes a reduction in its pH, making the skin more acidic. Each smart bandage contains a chemical called bromophenol blue, and when it encounters a more acidic environment, it turns yellow. Thus, when a smart bandage turns yellow, it's telling you that bacteria is present, but that it's antibiotic-sensitive.
If there's no infection, the covering remains its original green color.
Tests and cures
Image source: Khamkhlai Thanet/Shutterstock
The bandages have so far been tested on mice who were infected with one of two different strains of E. Coli bacteria, one antibiotic-sensitive, and one antibiotic-resistant. The smart coverings over the mice's wounds behaved as designed, turning the hoped-for colors over the course of a day or two. After some tweaking, that time — and the identification of bacteria — was reduced to just 2-4 hours.
An additional feature is that the design of their MOF causes UV light shined on them to produce reactive oxygen species (ROS) that puncture the protective membranes surrounding the bacterial cells. This restores their susceptibility to standard antibiotics, meaning that the bandages are both diagnostic and curative.
Given the construction simplicity of the bandages, the researchers are hopeful that they can be easily manufactured at scale to join the fight against antibiotic-resistant bacteria, which is currently credited with 700,000 deaths annually.
Being able to quickly identify resistant bacteria can help prolong the effectiveness of available treatments. As the study puts it, "Because of the "auto-obsolescence" of antibacterial treatments, it is an important issue in the current antibacterial field how to rationally use of existing antibiotics and overcome tolerance."
The physical action of handwashing plus the properties of soap is a one-two punch for the virus.
- A common recommendation from experts to help protect against coronavirus is to wash your hands often, but why? It turns out that each time you do it is an effective two-pronged attack.
- As Kate the Chemist explains, the virus has a weak outer membrane. By using the proper handwashing technique, you're actually breaking through that membrane and ripping the virus apart.
- Soap is an important part of the equation because of its two sides: the hydrophobic side (which grabs onto the virus), and the hydrophilic side (which grabs onto the water). Washing your hands with soap for at least 20 seconds allows the virus to be rinsed away.
Most homes are using insufficient methods to determine when chicken is done cooking and safe to eat.
- Checking the inside color of chicken is not a sufficient way to test its doneness.
- According to experts, the best way to ensure that chicken is safe to eat is to cook it to an internal temperature of 165°F (74°C).
- From 2009 to 2015, more than 3,100 people were sickened by chicken.
Forget the color-check method<p>While this is a common technique used by half of the households in the survey, the researchers reported that the color of the inside of a chicken changes at temperatures that are too low to kill common poultry pathogens like <a href="https://www.healthline.com/health/salmonella-enterocolitis" target="_blank"><em>salmonella</em></a><em>,</em> <a href="https://www.cdc.gov/foodsafety/diseases/clostridium-perfringens.html" target="_blank"><em>clostridium perfringens</em></a><em>,</em> and the most common,<em> Campylobacter</em>. According to the United States Department of Agriculture, poultry that is sufficiently cooked and safe to eat can come in shades of white, pink, and tan just like insufficiently cooked poultry.</p><p>Thermometers are perhaps the most reliable ways of indicating if a chicken is safe to eat, but less than 1.3 percent of households in the study used them while cooking chicken. </p>
Chicken pathogens<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a95b7b0158b3bdc4ce0ac2c880cc75b4"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/-yxA3r0xI-A?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>In addition to being the most popular meat in the United States, chicken is also the number one cause of foodborne illnesses. <a href="https://www.cdc.gov/mmwr/volumes/67/ss/ss6710a1.htm" target="_blank">According to a CDC study</a>, 3,113 people reported being sickened by chicken via the National Outbreak Reporting System web app between 2009 and 2015, more than by any other food category.</p><p>Eating undercooked chicken can cause foodborne illness with symptoms like fever, diarrhea, digestive malfunction, abdominal cramps, vomiting, and dehydration. This affects more than 1 million people in the United States every year, according to the <a href="https://www.cdc.gov/foodsafety/chicken.html" target="_blank">CDC</a>. <a href="https://www.mayoclinic.org/diseases-conditions/salmonella/symptoms-causes/syc-20355329" target="_blank"><em>Salmonella</em> symptoms</a> typically begin 6 hours to 6 days after infection, and can last from 4 to 7 days. Symptoms associated with a <em>Campylobacter</em> infection start 2 to 5 days after the infection and can last up to a week. As for <em>C.</em> <em>perfringens</em>, the symptoms come on suddenly, typically occurring between 8 to 12 hours after infection, and last for less than 24 hours. Unlike <em>s</em><em>almonella</em> and <em>Campylobacter</em>, vomiting and a high fever are not symptoms associated with <em>C.</em> <em>perfringens</em>.</p>
How to safely prepare chicken<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzI0MzIyNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTU5NzI3NzAyOX0.Iask-3R_e3L6BkrXCDrRBeuLPmM6IjtO05KKqNPjlj4/img.jpg?width=980" id="0685c" class="rm-shortcode" data-rm-shortcode-id="a191cb3ffdf863e3a4f164c222a29474" data-rm-shortcode-name="rebelmouse-image" alt="chicken dish" />
Dr. Kate Biberdorf explains why boiling water makes it safer and how water molecules are unusual and cool.
- University of Texas professor and science entertainer Kate the Chemist joined Big Think to talk about water molecules and to answer two interesting and important questions: Why does boiling water make it safe to drink, and what happens to water when you boil or freeze it?
- According to Kate, when water is heated to a certain temperature (100°C/ 212°F) the hydrogen bonds break and it goes from a liquid to a gas state. Boiling for a minimum of 5 minutes kills any viruses and bacteria that were in the water.
- "Water is a freak and so it is one of my favorite molecules ever," Kate says. "It has these unique properties and we are surrounded by it constantly. We also are made of water. We have to drink water to survive...It's a really, really fun molecule to investigate."
A drug developed to combat Alzheimer’s Disease can trigger regeneration of tooth dentin.
- New research into the drug Tideglusib clarifies what it can do for damaged teeth.
- Tooth dentin can be regrown instead of needing to be replaced with man-made composite.
- Only particular cavities need apply.
Three layers in a tooth<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjg3NzgxOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NDA0Nzc2OH0.QsXz027CceQ07PkkGx-dKtCK0Nd2Y4DVUyYxOKRguAY/img.jpg?width=980" id="b7413" class="rm-shortcode" data-rm-shortcode-id="ef9695c4011648e70d7ec0eb01ac5009" data-rm-shortcode-name="rebelmouse-image" />
Image source: BruceBlaus Wikimedia<p>The are three elements to the structure of a tooth:</p><ul><li>The outer <a href="https://en.wikipedia.org/wiki/Tooth_enamel" target="_blank">enamel</a> — The hard outer mineralized layer that protects the tooth structure</li><li>The <a href="https://en.wikipedia.org/wiki/Dentin" target="_blank">dentin</a> — Hard, calcified tissue protecting the structure's soft inner regio.</li><li>The soft <a href="https://en.wikipedia.org/wiki/Pulp_(tooth)" target="_blank">dental pulp</a> — The inside of the tooth. It contains the tooth's nerve, blood vessels, and connective tissue.</li></ul><p>When you get a <a href="https://www.mayoclinic.org/diseases-conditions/cavities/symptoms-causes/syc-20352892" target="_blank">cavity</a>, the outer enamel has a hole in it. With that outer protection breached, infecting bacteria nestle in, causing decay that burrows ever-deeper into the tooth, causing damage to its inner layers. To repair it using traditional methods, a dentist cleans bacteria from out the inside of cavity before filling it with a cement composite that replaces the lost natural dentin.</p>
Building new dentin<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjg3NzgxOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTU5NTUwMDUzNX0.PUqkWg-3tXjk13Q6E-KoLVuD1Kk76Q-GF7qsDou9YCQ/img.jpg?width=980" id="fbfbe" class="rm-shortcode" data-rm-shortcode-id="27c6d0e4092f3e137784de219d79aa10" data-rm-shortcode-name="rebelmouse-image" />
Image source: Quang Tri Nguyen/Unsplash<p style="margin-left: 20px;"><em>"In the last few years we showed that we can stimulate natural tooth repair by activating resident tooth stem cells. This approach is simple and cost effective. The latest results show further evidence of clinical viability and brings us another step closer to natural tooth repair." — lead author Paul Sharpe</em></p><p>Share and his colleagues were interested in understanding how large a damaged area could be repaired with Tideglusib, and where, and they hoped to analyze the composition of repaired dentin in comparison to naturally occurring dentin and/or bone.</p><p>The researchers confirmed that Tideglusib can cause the generation of sufficient replacement dentin to be of use. The paper asserts that the drug can "fully repair an area of dentin damage up to 10 times larger." More than enough to be of value.</p><p>Second, Sharpe and his team learned that Tideglusib works only on a particular kind of tooth material: the coronal pulp, that region of pulp extending to the crown of the tooth. They also learned that the drug must be applied <em>only</em> to the affected area to be effective, finding that untreated areas of pulp, notably the root pulp, are not adversely affected by treatment, a good thing.</p><p>Finally, analyzing repaired dentin using <a href="https://en.wikipedia.org/wiki/Raman_spectroscopy" target="_blank">Raman microspectroscopy</a>, the researchers determined that the generated dentin is chemically quite similar to natural dentin, being comprised of a similar ratios of carbonate and phosphate and mineral-to-matrix as natural dentin. </p>