SOUTHWESTRETORT
SEVENTY-SEVENTH YEAR
October 2024
Published for the advancement of Chemists, Chemical Engineers and Chemistry in this area published by
The Dallas-Fort Worth Section, with the cooperation of five other local sections of theAmerican Chemical Society in the Southwest Region.
Vol. 77 (2) October 2024
Editorial and Business Offices: Contact the Editor for subscription and advertisement information.
Editor: Connie Hendrickson: retort@acsdfw.org
Copy and Layout Editor: Lance Hughes: hugla64@gmail.com
Business Manager: Martha Gilchrist: Martha.Gilchrist@tccd.edu
The Southwest Retort is published monthly, September through May, by the Dallas-Ft. Worth Section of the American Chemical Society, Inc., for the ACS Sections of the Southwest Region.
2024ACS DFW Executive Committee
Chair: Rajani Srinivasan
Chair-elect: Denise Lynn Merkle
Past Chair: Michaela C. Stefan
Treasurer: Martha Gilchrist
Secretary: Trey Putnam
Councilors:
MaryAnderson
Kirby Drake
Linda SchultzR
Rebecca Weber
Alternate Councilors:
Michael Bigwood
Daniela Hutanu
Danny Tran
A new injectable to prevent and treat hypoglycemia From the ACS Press Room
“A Glucose-Responsive Glucagon-Micelle for the Prevention
of
Hypoglycemia” ACS Central Science
People with diabetes take insulin to lower high blood sugar. However, if glucose levels plunge too low from taking too much insulin or not eating enough sugar people can experience hypoglycemia, which can lead to dizziness, cognitive impairment, seizures or comas. To prevent and treat this condition, researchers in ACS Central Science report encapsulating the hormone glucagon. In mouse trials, the nanocapsules activated when blood sugar levels dropped dangerously low and quickly restored glucose levels.
Glucagon is a hormone that signals the liver to release glucose into the bloodstream. It’s typically given by injection to counteract severe hypoglycemia in people who have diabetes. While an emergency glucagon injection can correct blood sugar levels in about 30 minutes, formulations can be unstable and insoluble in water. In some cases, the hormone quickly breaks down when mixed for injections and clumps together to form toxic fibrils. Additionally, many hypoglycemic episodes occur at night, when people with diabetes aren’t likely to test their blood sugar. To improve commercial glucagon stability and prevent hypoglycemia, Andrea Hevener and Heather Maynard looked to micelles: nanoscale, soap-like bubbles that can be customized to assemble or disassemble in different environments and are used for drug delivery. They developed a glucoseresponsive micelle that encapsulates and protects glucagon in the bloodstream when sug-
ar levels are normal but dissolves if levels drop dangerously low. To prevent hypoglycemia, the micelles could be injected ahead of time and circulate in the bloodstream until they are needed.
Encapsulated glucagon for insulin-induced hypoglycemia dissolves when sugar levels get seriously low (less than 60 milligrams per deciliter, mg/dL), releasing the hormone into the bloodstream and triggering the liver to release glucose. At normal sugar levels (more than 100 mg/dL), the micelles remain intact, keeping glucagon inactive. Adapted from ACS Central Science 2024, DOI: 10.1021/ acscentsci.4c00937
In lab experiments, the researchers observed that the micelles disassembled only in liquid environments that mimicked hypoglycemic conditions in both human and mice bodies: less than 60 milligrams of glucose per deciliter. Next, when mice experiencing insulininduced hypoglycemia received an injection of the specialized micelles, they achieved normal blood sugar levels within 40 minutes. The team also determined that glucagonpacked micelles stayed intact in mice and
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From the ACS Press Room
Spinning artificial spider silk into next-generation medical materials
“Overexpressed Artificial Spidroin Based Microneedle Spinneret for 3D Air Spinning of Hybrid Spider Silk”
ACS Nano
It’s almost time to dust off the Halloween decorations and adorn the house with all manner of spooky things, including the classic polyester spider webs. Scientists reporting in ACS Nano have made their own version of fake spider silk, but this one consists of proteins and heals wounds instead of haunting hallways. The artificial silk is strong enough to be woven into bandages that helped treat joint injuries and skin lesions in mice.
Spider silk is one of the strongest materials on Earth, technically stronger than steel for a material of its size. However, it’s tough to obtain spiders are too territorial (and cannibalistic!) to breed them like silkworms, leading scientists to turn to artificial options. Teaching microbes to produce the spider silk proteins through genetic engineering is one such option, but this has proved challenging because the proteins tend to stick together, reducing the silk’s yield. So, Bingbing Gao and colleagues wanted to modify the natural protein sequence to design an easily spinnable, yet still stable, spider silk using microbes.
The team first used these microbes to produce the silk proteins, adding extra peptides as well. The new peptides, following a pattern found in the protein sequence of amyloid
polypeptides, helped the artificial silk proteins form an orderly structure when folded and prevented them from sticking together in solution, increasing their yield. Then, using an array of tiny, hollow needles attached to the nozzle of a 3D printer, the researchers drew the protein solution into thin strands in the air and spun them together into a thicker fiber. This setup acted like a giant artificial spider spinning its web.
Scientists are creating artificial spider silk by drawing strands from an array of tiny hollow needles, as shown here, similar to how arachnids do it.
They then wove their artificial silk fibers into prototype wound dressings that they applied on mice with osteoarthritis (a degenerative
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From the ACS Press Room
Alleviating depression in mice by restoring gut microbiome
“Antioxidant Carbon Dots Nanozymes Alleviate Stress-Induced Depression by Modulating Gut Microbiota”
Langmuir
Depression is a significant challenge to diagnose and treat. Among the factors influencing depression onset and severity, there is growing evidence for chemical imbalances that generate oxidative stress throughout the body. To address this problem, researchers reporting in the ACS journal Langmuir developed antioxidant carbon dot nanozymes (synthetic enzyme-like substances) that reduced oxidative stress, rebalanced gut microbes and alleviated stressinduced depression in rats.
individuals but also challenge public health and economic prosperity. One of the potential hallmarks of depressive disorder is a buildup of reactive oxygen- and nitrogencontaining compounds, which can overwhelm the body’s natural defenses. And the resulting oxidative stress impacts gut health by disrupting the balance of microbes, which can trigger inflammation and alter brain and neuronal function. To correct this problem, Jihong Huang, Weiwei He and colleagues synthesized enzyme-like substances with strong antioxidant capacity to reduce the reactive species and thereby restore gut microbe balance and alleviate depression.
The researchers created carbon dot nanozymes (CDzymes) by polymerizing glucose and the amino acid histidine to ensure antioxidant activity while maintaining biocompatibility. The CDzymes neutralized a range of reactive species in solution and in cultured mouse nerve cells without signs of toxicity. The researchers then moved to a rat model of depression known as chronic and unpredictable mild stress (CUMS). They compared animals in four groups healthy rats, untreated CUMS rats, and CUMS rats treated with either gamma-aminobutyric acid (GABA), an antidepressant drug that inhibits nerve signaling, or CDzymes. Rats receiving either treatment displayed less depressive behavior than untreated CUMS rats in terms of reward-seeking, curiosity, willingness to explore and resistance to despair. The behavioral improvements observed with GABA or CDzymes treatment also aligned with im-
Mental health disorders such as depression not only reduce quality of life for affected
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From the ACS Press Room
Plastic-eating enzyme identified in wastewater microbes
“Mechanisms of Polyethylene Terephthalate Pellet Fragmentation into Nanoplastics and Assimilable Carbons by Wastewater Comamonas”
Environmental Science & Technology
Plastic pollution is everywhere, and a good amount of it is composed of polyethylene terephthalate (PET, ♳). This polymer is used to make bottles, containers and even clothing. Now, researchers report in ACS’ Environmental Science & Technology that they have discovered an enzyme that breaks apart PET in a rather unusual place: microbes living in sewage sludge. The enzyme could be used by wastewater treatment plants to break apart microplastic particles and upcycle plastic waste.
Microplastics are becoming increasingly
Treated wastewater can contain microplastics, but researchers have found a plastic-busting enzyme that could help degrade the pesky particles. Shutterstock.com/DedMityay
prevalent in places ranging from remote oceans to inside bodies, so it shouldn’t be a surprise that they appear in wastewater as well. However, the particles are so tiny that they can slip through water treatment purifi-
cation processes and end up in the effluent that is reintroduced to the environment. But effluent also contains microorganisms that like to eat those plastic particles, including Comamonas testosteroni so named because it degrades sterols like testosterone. Other bacterial species, including the common E. coli, have previously been engineered to turn plastic into other useful molecules. However, C. testosteroni naturally chews up polymers, such as those in laundry detergents, and terephthalate, a monomer building block of PET. So, Ludmilla Aristilde and colleagues wanted to see if C. testosteroni could also produce enzymes that degrade the PET polymer.
The team incubated a strain of C. testosteroni with PET films and pellets. Although the microbes colonized both shapes, microscopy revealed that the microbes preferred the rougher surface of the pellets, breaking them down to a greater degree than the smooth films. To better simulate conditions in wastewater environments, the researchers also added acetate, an ion commonly found in wastewater. When acetate was present, the number of bacterial colonies increased considerably. Though C. testosteroni produced some nano-sized PET particles, it also completely degraded the polymer to its monomers compounds that C. testosteroni and other environmental microbes can use as a source of carbon to grow and develop, or even convert into other useful molecules, according to the team.
Next, the researchers used protein analysis to identify the key enzyme that gives this mi-
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From the ACS Press Room
Research update: Recreational tubing, swimming leaves an impact on streams
“Assessing the Impact of Recreational Activities on Streams: A Colorado Case Study”
ACS
ES&T Water
How does your dip in a local watering hole affect the stream’s chemistry? Researchers who previously analyzed the impact of people swimming and tubing on a Colorado creek report updated observations in ACS ES&T Water. They find that these recreational activities over a busy Labor Day weekend have a short-term effect, increasing the levels of metals, human gutassociated microbes and substances from personal care products.
Researchers James Ranville, Carsten Prasse, John Spear, Noor Hamden, Carmen Villarruel and colleagues studied how recreational activities, such as float tubing, around the 2022 Labor Day weekend affected a natural stream’s chemistry and microbiome. They presented a preliminary assessment of chemical and microbial constituents at ACS Fall 2023, a meeting of the American Chemical Society. Now, the researchers have expanded the analyses in Colorado’s Clear Creek to include additional organic contaminants. They sampled water downstream of a busy area with people tubing and swimming and compared the results to an undisturbed location upstream and a day with no one at the two sites. Their observations indicate changes in:
• Metals: People in the stream stirred up sediment, resuspending particles con-
taining copper, lead and zinc into the water.
• Microbial community: The abundance of microorganisms associated with the human gut microbiome increased when people were present, but the stream returned to an undisturbed, background microbiome within 48 hours.
• Organic compounds: Analyses detected a broad spectrum of compounds such as ones from personal care products, including makeup and hair styling products, as well as insect repellants. Some, such as the pain killer acetaminophen, suggest human excretion in the stream as well.
Researchers continue investigating the impact of tubing on water quality in streams. Amam ka/ Shutterstock.com
While high levels of tubing and swimming impacted the stream, the results from the study suggest that these types of human activities didn’t have long-term effects. However, the researchers say that native creek organisms could react negatively to prolonged or repeated exposure to metals, microbes associated with humans, or organic compounds of concern.
The authors acknowledge funding from the National Science Foundation and Johns Hopkins University.
Highlights
of Fall 2024 ACS meeting (Denver)
by Mary Anderson, DFW Councilor
The meeting was exciting and fast paced in delightful Denver.
The attendance was very good: 11,065 (9845 in person, 1220 virtual); of these 3802 were first time attendees.
There were more than 9000 abstracts, including 2413 posters; with 40 networking events.
FinanciallyACS is doing just fine.
And there will be NO increase in membership dues for 2025!!
The number of paid members is 99,126 a small increase over 2023! There are 2853 SocietyAffiliates, and 115,085 CommunityAssociates! The numbers are up!
Please note there are various discounts and joint memberships available, e.g. with AACT, NOBCChE,AISES, and hopefully soon SACNAS.
ACS Elections are live! Please cast your vote!
Also, if you choose to nominate someone: https://nominations.acs.org/form The Southwest Regional Meeting (SWRM) is October 20-23 in Waco. I hope to see you all there!
TheACS Spring meeting is in San Diego in March!
From the ACS Press Room
Treating radiation wounds with aspirin hydrogels
“Multifunctional Glycopeptide-Based Hydrogel via Dual-Modulation for the Prevention and Repair of Radiation-Induced Skin Injury”
ACS Biomaterials Science & Engineering
Radiation is a powerful tool for treating cancer, but prolonged exposure can damage the skin. Radiation-induced skin injuries are painful and increase a person’s chances of infection and long-term inflammation. Now, researchers in ACS Biomaterials Science & Engineering report an aspirin-containing hydrogel that mimics the nutrient-rich fluid between cells and accelerates healing of skin damaged by radiation in animals. With further development, the new salve could provide effective and rapid wound healing for humans.
Most people undergoing radiotherapy for cancer will experience radiation-induced skin injury that can include redness, pain, ulcers, necrosis and infection. There are few treatments for these wounds, with the most common methods being debridement (surgical removal of the damaged skin) and hyperbaric oxygenation (exposure to pure oxygen in a pressurized environment). Wound dressings made from hydrogels are gaining popularity because they are easy to apply and provide a wet environment for healing that is similar to the inside of the body. Glycopeptide-based hydrogels are especially promising: In laboratory and animal studies, the nanofiber structures have promoted cellular growth and regulated cell adhesion and migration.Aresearch team led by Jiamin Zhang, Wei Wang, Yumin Zhang and Jianfeng Liu proposed
loading aspirin, a common anti-inflammatory drug, into a glycopeptide-based hydrogel to create a multifunctional wound dressing for radiation-induced skin injuries.
In lab tests with cultured cells, the researchers found that the aspirin-contained hydrogel scavenged reactive oxygen species, repaired DNAdouble-strand breaks and inhibited inflammation caused by radiation exposure without affecting cellular growth. In mouse models of radiation-induced skin injury, the researchers found that dressing wounds for three weeks with the salve reduced acute injuries and accelerated healing results that the team says point to its potential as an easy -to-administer, on-demand treatment option for reducing radiation damage and promoting healing in humans.
The authors acknowledge funding from the Chinese Academy of Medical Sciences’ Innovation Fund for Medical Sciences and National Natural Science Foundation of China.
Anew aspirin-embedded hydrogel could be an on-demand option for healing skin damaged during radiation therapy. Mark_Kostich/Shutterstock.com
From the ACS Press Room
Fruit juice offers a fresh take on kombucha
“Physicochemical Properties, Antioxidant Activity, and Sensory Profiles of Kombucha and Kombucha-Like Beverages Prepared Using Passion Fruit (Passiflora edulis) and Apple (Malus pumila)”
ACS Agricultural Science & Technology
Kombucha is a fizzy, tangy drink made by fermenting tea. But brewers are now fermenting other plant-based drinks to explore nutritional properties and flavors. Researchers in ACS Agricultural Science & Technology compared the biochemistry and flavor of kombucha with brews made from apple and passion fruit juices. They found that the apple beverage contained high levels of bioactive compounds called flavonoids and ranked highly among taste testers, signaling its promise as a kombucha alternative.
Researchers brewed kombucha (left) and kombucha-like beverages from passion fruit (center) and apple (right) juices and found that the apple-based drink had the most flavonoids and ranked most favorable among a panel of taste testers.
Adapted fromACSAgricultural Science & Technology 2024, DOI:10.1021/acsagscitech.4c00372
To make kombucha, brewers ferment sweet-
ened tea with a spongy disk of microbes known as a SCOBY, or symbiotic culture of bacteria and yeast. The resulting beverage contains beneficial bacteria from the fermentation process and bioactive compounds from the tea, including flavonoids, phenolics and anthocyanins that may have antioxidant and anti-inflammatory properties. Few studies have investigated whether liquids other than tea could be brewed as kombucha-like beverages with boosted antioxidant levels or unique flavors. So, Socorro Vanesca, Frota Gaban and coworkers fermented antioxidant-rich apple and passion fruit juices with a SCOBY to find out.
After fermenting apple juice, passion fruit juice, and tea in separate jars for 10 days at room temperature, the researchers measured the levels of several bioactive compounds in each brew and found that:
• The apple beverage had the highest level of flavonoids, followed by kombucha and the passion fruit drink.
• The kombucha and apple beverages had comparable levels of phenolic compounds that were higher than those of the passion fruit beverage.
• All three brews had similar amounts of anthocyanin, a red-colored antioxidant.
• The researchers asked 12 volunteer taste testers to evaluate each beverage’s color, aroma and flavor. The taste testers noted an amber color for the apple beverage, yellow for passion fruit and gold for the kombucha. The volunteers reported stronger, fruitier aromas
Continued on page 15
From the ACS Press Room
continued
A new injectable to prevent and treat hypoglycemia
Continued from page 5
didn’t release the hormone unless blood glucose levels fell below the clinical threshold for severe hypoglycemia. From additional toxicity and biosafety studies in mice, the researchers note that empty micelles didn’t trigger an immune response or induce organ damage.
While more studies are needed, the researchers say their proof-of-concept is a first step toward a new on-demand and effective method for preventing or mitigating extremely low blood sugar levels.
The authors acknowledge funding from the Leona M. and Harry B. Helmsley Charitable Trust; BioPACIFIC Materials Innovation Platform funded by the National Science Foundation; the National Science Foundation Graduate Research Fellowship Program; the National Institutes of Health; and the University of California, Los Angeles Clinical and Translational Science Institute.
Spinning artificial spider silk
Continued from page 6
joint disease) and chronic wounds caused by diabetes. Drug treatments were easily added to the dressings, and the team found these modified dressings boosted wound healing better than traditional bandages. Compared
with a control group with neutral dressings, mice with osteoarthritis showed decreased swelling and repaired tissue structure after 2 weeks of treatment, while diabetic mice with skin lesions treated with a similar dressing showed significant wound healing after 16 days of treatment. The new silken bandages are biocompatible and biodegradable, and the researchers say that they show promise for future applications in medicine.
The authors acknowledge funding from the National Key R & D Program of China, the National Natural Science Foundation of China, the Postgraduate Research & Practice Innovation Program of Jiangsu Province, the Nanjing Tech University Teaching Reform Project, the Discipline Fund of Nanjing Tech University School of Pharmaceutical Sciences, and the Cultivation Program for The Excellent Doctoral Dissertation of Nanjing Tech University.
Alleviating depression in mice
Continued from page 7
proved levels of several depression-related neurotransmitters isolated from brain tissues. The researchers then explored the impact of CUMS and treatment on the rodents’gut microbiome by analyzing fecal microbes. Although microbial richness and diversity was greatly reduced in the depressed animals, this reduction was largely reversed to the same degree with GABA or CDzymes treatment. Additionally, the types of microbes
From the ACS Press Room
continued
present in the feces of treated rats was much closer to that of healthy rats, highlighting the link between gut health and mental health. This microbial restoration also resulted in improved metabolism of several amino acids critical to nerve signalling. Taken together, these results present CDzymes as effective as GABAin animal studies, making it another potential therapeutic option for addressing depressive disorder.
The authors acknowledge funding from the Central Government Guides the Local Science and Technology Development Special Fund, the Key Research and Development Project of Henan Province, and the Collaborative Innovation Center of Functional Food by Green Manufacturing.
Plastic-eating enzyme identified
Continued from page 8
crobe its plastic-eating abilities. Though this new enzyme was distinct from previously described PET-busting enzymes based on its overall protein sequence, it did contain a similar binding pocket that was responsible for PET breakdown. When the gene encoding for this key enzyme was placed into a microbe that doesn’t naturally degrade PET, the engineered microbe gained the ability to do so, proving the enzyme’s functionality. The researchers say that this work demonstrates C. testosteroni’s utility for upcycling PET and PET-derived carbons, which could help reduce plastic pollution in wastewater.
The authors acknowledge funding from the U.S. National Science Foundation, the U.S. Department of Energy, the Office of Energy Efficiency and Renewable Energy, the Advanced Materials and Manufacturing Technologies Office, and the Bioenergy Technologies Office as part of the BOTTLE Consortium.
Fruit juice offers a fresh take on kombucha
Continued from page 13
for the fermented fruit juices compared with the tea. However, the passion fruit drink tasted more bitter than the sweeter apple and tea drinks, both of which received equal votes as the favorite beverage. Because fermented apple juice has more flavonoids and a pleasant taste compared with the other beverages, the researchers say it could be a successful alternative to kombucha made from tea. They plan to explore health benefits and flavors of other fermented fruits in the future.
The authors acknowledge funding from the Coordination for the Improvement of Higher Education Personnel.
From the Editor
The first time I heard about protein structure was in my first biochemistry course (over 50 years ago). Ever since that time, I have been entranced with the idea of spontaneous protein folding conducted and orchestrated by the order of amino acids forming the protein. The idea of such a complex three-dimensional structure forming spontaneously from what is essentially a one-dimensional chain fascinated me. I was not the only one; in my son’s essay for graduate school, he mentioned that very thing (and that was not something we had ever discussed). We weren’t the only ones!
This fall, the Royal SwedishAcademy of Sciences awarded the Nobel Prize in Chemistry 2024, with one half to David Baker (University of Washington, Seattle, WA, and Howard Hughes Medical Institute, USA) for computational protein design, and the other half jointly to Demis Hassabis and John M. Jumper (Google DeepMind, London, UK) for protein structure prediction.
They have cracked the code for proteins’ amazing structures! Here is the link to the press release: https://www.nobelprize.org/prizes/chemistry/2024/press-release/
