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Weed-killer Compounds also Kill Parasite sometimes found in Cat Feces D Printing Smart Clothes with a new Liquid
From the ACS Press Room Weed-killer Compounds also Kill Parasite sometimes found in Cat Feces
“Oxadiazon Derivatives Elicit Potent Intracellular Growth Inhibition against Toxoplasma gondii by Disrupting Heme Biosynthesis” ACS Infectious Diseases
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The parasite Toxoplasma gondii infects up to one-third of the human population, experts say. Sometimes transmitted to humans from infected cat feces or litter, the protozoan can cause severe and even deadly illnesses in immunocompromised people and fetuses. Now, researchers reporting in ACS Infectious Diseases have discovered that common herbicides and some of their derivatives can kill the parasite when it infects human cells in a petri dish, without harming the cells themselves. T. gondii infection usually occurs from eating undercooked contaminated meat, exposure to infected cat feces or mother-to-child transmission during pregnancy. The parasite causes mild or no symptoms in most people, but it can cause severe illnesses in immunocompromised people and birth defects in the fetuses of pregnant women. Current therapies have limitations, such as strong side effects and an inability to cross the placenta to treat the fetus. They also don’t work well for chronic infections. Recently, scientists discovered that T. gondii expresses an enzyme (protoporphyrinogen oxidase, or PPO) that more closely resembles the plant version of the enzyme than the mammalian one. Plant PPO, which helps make an essential com-
pound called heme, is the target of some common herbicides, including oxadiazon. Kerrick Rees, Zhicheng Dou and Daniel Whitehead wondered if these herbicides or their derivatives could kill not only weeds, but also T. gondii — without harming human cells.
The researchers screened several herbicides for the ability to kill T. gondii that had infected human cells in a dish, finding that oxadiazon and a related compound, oxadiargyl, were the most effective. Then, they synthesized 18 derivatives of oxadiargyl that had different chemical groups at a certain region of the molecule, identifying some that were even more potent than the parent compound. In other experiments, the researchers confirmed that the herbicide derivatives work primarily by inhibiting PPO. Importantly, the compounds didn’t harm human cells that hosted the parasites. Next, the researchers plan to test the most potent molecules in an animal model of T. gondii infection. The authors acknowledge funding from the National Institutes of Health.
From the ACS Press Room D Printing Smart Clothes with a new Liquid Metal-Alginate Ink (video)
“Liquid Metal Microgels for ThreeDimensional Printing of Smart Electronic Clothes”
ACS Applied Materials & Interfaces
In the future, smart clothing might monitor our posture, communicate with smartphones and manage our body temperature. But first, scientists need to find a way to costeffectively print intricate, flexible and durable circuits onto a variety of fabrics. Now, researchers reporting in ACS Applied Materials & Interfaces have developed a conductive 3D printing ink made of liquid metal droplets coated with alginate, a polymer derived from algae. Watch a video about the new ink here. Youtube ID: hyEGK8NmCiI Conventional electronics are rigid and unable to withstand the twisting and stretching motions that clothing undergoes during typical daily activities. Because of their fluid nature and excellent conductivity, gallium-based liquid metals (LMs) are promising materials for flexible electronics. However, LMs don’t stick well to fabrics, and their large surface tension causes them to ball up during 3D printing, rather than form continuous circuits. Yong He and colleagues wanted to develop a new type of conductive ink that could be 3D printed directly onto clothing in complex patterns.
To make their ink, the researchers mixed LM and alginate. Stirring the solution and removing the excess liquid resulted in LM microdroplets coated with an alginate microgel shell. The ink was very thick until it was squeezed through a nozzle for 3D printing, which broke hydrogen bonds in the microgel and made it more fluid. Once the ink reached the fabric surface, the hydrogen bonds reformed, causing the printed pattern to maintain its shape. The team 3D printed the new ink onto a variety of surfaces, including paper, polyester fabrics, nonwoven fabrics and acrylic-based tape. Although the printed patterns were not initially conductive, the researchers activated them by stretching, pressing or freezing, which ruptured the dried alginate networks to connect the LM microdroplets.
After activation, the printed circuits had excellent electrical conductivity and strain sensing properties. In addition, applying a small voltage to the ends of the circuit caused it to heat up, even in very cold temperatures. To demonstrate the ink’s capabilities, the team 3D printed a series of electronics onto commercial clothing. On a T-shirt, they printed a near-field communication tag that directed a smartphone placed nearby to open a web site. Other sensors printed on clothing monitored the motion of an elbow or knee joint. And a
From the ACS Press Room
circuit powered by a small battery heated up the printed pattern to above 120 F in less than a minute. The LM-alginate ink can be recycled by soaking the fabric in a weak sodium hydroxide solution, recovering fresh liquid metal for new applications. The authors acknowledge funding from the National Natural Science Foundation of China and the National Key Research and Development Program of Zhejiang Province.
Continued from page 11 because some liquid medications are alcohol-based, the researchers placed a coded silk film in a clear bottle of Scotch whisky, and found that the fluorescent code was still readable with the app. Finally, the researchers showed that the fluorescent silk proteins are broken down by gastrointestinal en-
“zymes, suggesting that the silk codes are not only edible but also can be digested by the Earthworms” Continued from page 12 body. The researchers say that placing these mixed with either microscopic PLA or PET particles. Analysis of the creatures’ excretions showed that their digestive systems broke down PLA into much smaller fragedible code appliqués onto pills or in liquid doses could empower patients and their care providers to avoid the unintentional consumption of fake treatments. ments than was observed with PET plastics. The authors acknowledge funding from the The animals also excreted PLA much more Cooperative Research Program for Agriculslowly. The researchers say the results ture Science & Technology Development show that earthworms can promote the from Rural Development Administration of breakdown of bioplastics, such as PLA, in the Republic of Korea, the U.S. Air Force soil. They add that more studies are needed Office of Scientific Research and the Trask to determine how the slow excretion of Innovation Fund from Purdue University. PLA fragments affects the health of these Silkworms can produce edible, fluorescent animals and whether the worms are an op- silk cocoons (left side of left image); the tion to remove degradable plastics from the proteins from the cocoons can be used in environment. codes (right) to verify the authenticity of The authors acknowledge funding from a medications. National Key Research and Development Project of China, the National Natural Science Foundation of China, the Tianjin Municipal Science and Technology Bureau, the Ministry of Education (China) and the Tianjin Research Innovation Project for Postgraduate Students.
Around the Area
UT-Arlington
Adjunct Professor E. Thomas Strom has been chosen as one of the initial HIST Fellows. The program honors members of the ACS Division of the History of Chemistry who have made a significant impact on the advancement of history in the chemical sciences as well as given dedicated service to the History Division. This initial group consists of ten Fellows. Tom was also chosen in 2009 as one of the initial group of ACS Fellows.
UT-Dallas
Professor Ray Baughman, Robert A. Welch Chair in Chemistry, was awarded a $450K grant from the Air Force Office of Scientific Research for developing Faster, Stronger, More Powerful, and More Efficient Large-stroke Electrochemical, Thermal, and Fuelpowered Yarn- and Fiber-based Artificial Muscles.
Professor Jie Zheng, Cecil H. and Ida Green Professor in Systems Biology Science and ClearNano Inc. were awarded a $100K NIH-SBIR grant (Advancing Fluorescence Imaging-guided Partial Nephrectomy with ClearGold nanoparticles) and a $368K NIH-STTR grant (Advance Early Detection of Lupus Nephritis with ClearGold nanoparticles). Associate Professor Jeremiah Gassensmith was awarded three grants, one from the Robert A. Welch Foundation, and two from Noble Panacea Labs (Enzymatically cleavable dendrimers for slow release of active ingredients in skincare products ($80K) and Tunable, Photodegradable Polymers for Cargo Delivery in Cosmetics ($72K)). Assistant Professor Sheena D’Arcy and Assistant Professor of Instruction Sumudu Wijenayake won UT Dallas School of Natural Sciences and Mathematics Teaching Awards for research professors and senior lecturers, respectively. Zhong Wang (graduate student in the Baughman Group) won the Best Dissertation Award in the School of Natural Sciences and Mathematics for 2022. Professor Kenneth J. Balkus, Jr. won the 2022 Robert H. Goddard Alumni Award for Outstanding Professional Achievement from Worcester Polytechnic Institute.
