NOVEMBER 2022 Southwest Retort

SOUTHWESTRETORT

SEVENTY-FIFTH YEAR

November 2022

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 the American Chemical Society in the Southwest Region.

Vol. 75(3) November 2022

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.

From the ACS Press Room

AI helps Researchers Design Microneedle Patches that Restore Hair in Balding Mice

“Machine Learning Guided Discovery of Superoxide Dismutase Nanozymes for Androgenetic Alopecia”

Nano Letters

Hair loss is undesirable for many men and women because one’s hairstyle is often closely tied to their self confidence. And while some people embrace it, others wish they could regrow their lost strands. Now, researchers reporting in ACS’ Nano Letters have used artificial intelligence (AI) to predict compounds that could neutralize baldness-causing reactive oxygen species in the scalp. Using the best candidate, they constructed a proof of concept microneedle patch and effectively regenerated hair on mice.

Most people with substantial hair loss have the condition androgenic alopecia, also called male or female pattern baldness. In this condition, hair follicles can be damaged by androgens, inflammation or an overabundance of reactive oxygen species, such as oxygen free radicals. When the levels of oxygen free radicals are too high, they can overwhelm the body’s antioxidant enzymes that typically keep them in check. Superoxide dismutase (SOD) is one of these enzymes, and researchers have recently created SOD mimics called “nanozymes.” But so far, those that have been reported aren’t very good at removing oxygen free radicals. So, Lina Wang, Zhiling Zhu and colleagues wanted to

see whether machine learning, a form of AI, could help them design a better nanozyme for treating hair loss.

The researchers chose transition-metal thiophosphate compounds as potential nanozyme candidates. They tested machine learning

Hair regrew thicker in mice treated with a manganese-nanozyme microneedle patch (right-side image, labeled MnMNP) compared to those treated with testosterone as a control (left-side image).

Credit: Adapted from Nano Letters 2022, DOI:

models with 91 different transition metal, phosphate and sulfate combinations, and the techniques predicted that MnPS3 would have the most powerful SOD like ability. Next, MnPS3 nanosheets were synthesized through chemical vapor transport of manganese, red phosphorus and sulfur powders. In initial tests with human skin fibroblast cells, the nanosheets significantly reduced the levels of reactive oxygen species without causing harm.

From the ACS Press Room

New Biomarker could help Diagnose Alzheimer’s Disease Early

“Site-specific Phosphor-tau Aggregationbased Biomarker Discovery for AD Diagnosis and Differentiation”

ACS Chemical Neuroscience

Adefinitive diagnosis of Alzheimer’s disease (AD) was once only possible after someone had died, but recent biomarker studies have led to the development of imaging and spinal fluid tests for those still living. However, the tests can only monitor severe disease, differentiating advanced AD from related disorders. Reporting in ACS Chemical Neuroscience, researchers have now identified a biomarker that could help physicians diagnose AD earlier, as a patient transitions into mild cognitive impairment (MCI).

When hunting for AD biomarkers, some researchers have turned to the study of subtle changes in a protein called tau. These changes, or posttranslational modifications, can make the tau protein more likely to clump, which leads to neuron loss and impaired memory. Two such modifications involve the phosphorylation of tau at specific amino acids, resulting in versions called p tau181 and p tau217. These biomarkers have been shown to effectively differentiate AD tissues from those of people with other neurodegenerative diseases. Because it’s helpful to have many biomarkers in the physicians’ toolbox, Bin Xu, Jerry Wang, Ling Wu and colleagues sought additional p-tau biomarkers that could be effective AD diagnostics, or that

could perhaps catch AD at its early stages. Using post mortem brain tissue from AD patients and non AD subjects, the researchers identified several p-tau biomarkers selectively associated with tau aggregation. Like p

tau181 and p-tau217, several of these biomarkers differentiated AD tissues from healthy controls. One in particular p tau198 also discriminated AD from two other neurodegenerative diseases in which tau is known to clump. Further experiments showed that p tau198 was as effective as p tau181 and p tau217 in these assays. Importantly, both p-tau 198 and p-tau217 also could differentiate brain tissue of patients with MCI an early sign of AD from

A new biomarker could help detect Alzheimer’s disease early, when symptoms are mild.

Credit: Robert Kneschke/Shutterstock.com

From the ACS Press Room

Clear Window Coating could Cool Buildings without Using Energy

“High-Performance Transparent Radiative Cooler Designed by Quantum Computing”

ACS Energy Letters

As climate change intensifies summer heat, demand is growing for technologies to cool buildings. Now, researchers report in ACS Energy Letters that they have used advanced computing technology and artificial intelligence to design a transparent window coating that could lower the temperature inside buildings, without expending a single watt of energy.

Studies have estimated that cooling accounts for about

This window film (held in fingers at top left) keeps rooms bright and cool by allowing visible light to pass in while reflecting invisible infrared and ultraviolet sunlight and radiating heat into outer space.

Credit: Adapted from ACS Energy Letters 2022, DOI: 10.1021/acsenergylett.2c01969

15% of global energy consumption. That demand could be lowered with a window coating that could block the sun’s ultraviolet and near infrared light the parts of the solar spectrum that typically pass through glass to

heat an enclosed room. Energy use could be reduced even further if the coating radiates heat from the window’s surface at a wavelength that passes through the atmosphere into outer space. However, it’s difficult to design materials that can meet these criteria simultaneously and can also transmit visible light, meaning they don’t interfere with the view. Eungkyu Lee, Tengfei Luo and colleagues set out to design a “transparent radiative cooler” (TRC) that could do just that. The team constructed computer models of TRCs consisting of alternating thin layers of common materials like silicon dioxide, silicon nitride, aluminum oxide or titanium dioxide on a glass base, topped with a film of polydimethylsiloxane. They optimized the type, order and combination of layers using an iterative approach guided by machine learning and quantum computing, which stores data using subatomic particles. This computing method carries out optimization faster and better than conventional computers because it can efficiently test all possible combinations in a fraction of a second. This produced a coating design that, when fabricated, beat the performance of conventionally designed TRCs in addition to one of the best commercial heat-reduction glasses on the market.

In hot, dry cities, the researchers say, the optimized TRC could potentially reduce cooling energy consumption by 31% compared

From the ACS Press Room

Intranasal COVID Vaccine that Works Against Variants in Animals

Artificial Cell

Membrane

Polymersome Based Intranasal Beta Spike Formulation as a Second Generation Covid 19 Vaccine”

ACS Nano

An intranasal vaccine against SARS CoV 2 could quickly get to the respiratory tract, where the virus most commonly causes symptoms. And a spray or droplets could be a more palatable option for people who fear needles. But so far, only a few countries have approved COVID nasal vaccines. Now researchers report in ACS Nano that they’ve developed one that can fight off the original virus and two variants in hamsters.

The current batch of injected COVID vaccines have been effective at combating SARS CoV 2 infection around the globe. But these shots enter the body in the muscle tissue, whereas the virus enters and causes many of the typical COVID symptoms in the respiratory tract. Thus, intranasal immunizations with a spray or droplets could be a better option. Although India and a couple of other countries have approved intranasal COVID vaccines in recent months, the road to formulating successful intranasal vaccines is not an easy one. For example, AstraZeneca announced this month that its intranasal candidate failed to produce a strong immune response in nasal tissues and offered less systemic protection than the intramuscular version. So, Madhavan Nallani, Pierre Vande-

papeliere and colleagues wanted to formulate an intranasal COVID vaccine that would stimulate an immune response both systemically and in the respiratory tract, and that would also work against SARS-CoV-2 variants.

An intranasal COVID vaccine could help block the virus where it enters the body.

Credit: Anna Tryhub/Shutterstock.com

The researchers based their vaccine on the spike protein from the SARS CoV 2 beta variant, separately encapsulating the antigen and an immune stimulating adjuvant into nanoparticles known as artificial cell membrane polymersomes. They packaged the two components separately so that they could more easily change the spike component to one from another variant if needed. Intramuscular co administration of the parts produced a strong immune response in both mice and hamsters. When the hamsters injected with

“

From the ACS Press Room

Chemical Clues to the Mystery of What’s Coating Stradivari

“A Nanofocused Light on Stradivari Violins: Infrared s-SNOM Reveals New Clues Behind Craftsmanship Mastery”

Analytical Chemistry

Stradivarius violins produce elegant music with a level of clarity that is unparalleled by modern instruments, according to some musicians. And it’s the finishing touches mysterious treatments applied hundreds of years ago by Antonio Stradivari that contribute to their unique look and sound. In a step toward unraveling the secret, researchers in ACS’ Analytical Chemistry report on a nanometer-scale imaging of two of Stradivari’s violins, revealing a protein based layer between the wood and varnish.

Previous studies have reported that some stringed instruments crafted by Stradivari have a hidden coating underneath the shiny varnish. This coating’s purpose would have been to fill in and smooth out the wood, influencing the wood’s resonance and the sound that’s produced. Knowing the components of this film could be key to replicating the historic instruments in modern times. So, Lisa Vaccari, Marco Malagodi and colleagues wanted to find a technique that would determine the composition of the layer between the wood and varnish of two precious violins the San Lorenzo 1718 and the Toscano 1690.

Using a technique previously used on historic violins, synchrotron radiation Fourier

’s Violins

A highly precise, nanometer scale imaging technique revealed a protein based layer between the wood and the varnish coating of these two Stradivarius violins.

Credit: Adapted from Analytical Chemistry 2022, DOI: 10.1021/acs.analchem.2c02965

transform infrared spectromicroscopy, the team found that both samples had an intermediary layer, but this method couldn’t differentiate the layer’s composition from the adjacent wood. Then they turned to infrared scattering-type scanning near field microscopy (IR s SNOM) to analyze the samples. The IR s SNOM apparatus includes a microscope that collects images tens of nanometers wide and measures the infrared light scattered from the coating layer and the wood to collect information about their chemical composition. The results of the new method showed that the layer between the wood and varnish of both

Shining Light on why Plastics Turn Yellow From the ACS Press Room

“Could Superficial Chiral Nanostructures Be the Reason Polyethylene Yellows as It Ages?”

ACS Applied Polymer Materials

If you own a retro gaming console or have an old roll of packing tape, you’ve seen how plastics turn yellow as they age. Though the cause of this color change has long been attributed to the formation of molecules that act as dyes the actual chemical changes that take place remained unexplained. Now, researchers reporting in ACS Applied Polymer Materials have identified surface based chiral nanostructures as the potential culprit.

For one of the most commonly used plastics, polyethylene, it’s long been suggested that ultraviolet (UV) light the same light that gives us sunburns initiates reactions in the backbone of the polymer’s structure that cause the yellow color change. However, though chemical changes to polyethylene’s polymeric backbone have been observed after exposure to UV light, those new structures cannot account for polyethylene’s yellowing. One emerging way to intentionally modify the color and the ways that plastics interact with light is to create nano sized “supramolecular” structures on their surfaces that impact plastics’ properties in a controllable way. Inspired by these surface-based technologies, Margaret M. Elmer-Dixon, Melissa A. Maurer-Jones and colleagues wanted to see if such nanostructures formed unintentionally by UV light could be the cause of polyethylene yellowing.

Plastics, like what was used for this clock’s face, yellow over time; researchers now might know why this happens for polyethelene.

Credit: Dmitriev Mikhail/Shutterstock.com

Understanding how and why polymers degrade with age is key to designing alternatives that can avoid these pathways, allowing plastic products to have a longer lifespan.

The researchers first investigated if potential structures formed on yellowed polyethylene films’ surfaces interacted with circularly polarized light, a type of light whose waves travel with a right or left handed rotation. The amount of circularly polarized light absorbed by the film in these experiments changed depending on the film’s orientation, suggesting that the yellowed plastic contains new chemical structures that are chiral, that is, they are directional and aren’t identical to their mirror images. Additional experiments showed that most of the degradation during film yellowing occurred on the surface of the

From the ACS Press Room

Your Medical Implant or Food Wrapper could Someday

“Poly(cannabinoid)s: Hemp-Derived Biocompatible Thermoplastic Polyesters with Inherent Antioxidant Properties”

ACS Applied Materials & Interfaces

With the legalization of hemp cultivation, products containing cannabidiol (CBD) have become popular. Many of these oils and creams claim to alleviate pain and other conditions, and now, new research reported in ACS Applied Materials & Interfaces suggests that CBD could have another function: as a bioplastic. The research team created a CBD-based bioplastic material that could one day be used in medical implants, food wrappers and more.

Cannabis (Cannabis sativa) is well known for the euphoric “high” it gives users, caused by a chemical called tetrahydrocannabinol (THC). Another component, CBD, is responsible for feelings of relaxation and calmness, but unlike THC, it doesn’t produce a high. In hemp plants bred to contain little to no THC, CBD can make up to 20% of the plant’s weight. Because it’s now federally legal in the U.S. to grow hemp, the price of CBD has dropped dramatically, opening up the possibility of using CBD in other applications.

In recent years, the bioplastic called poly (lactic acid), or PLA, has become a popular option for sustainable plastics because it’s made from corn and sugarcane instead of

fossil fuels, and can be industrially composted. Many single use consumer goods, such as

This melt processable CBD based polymer looks and works like a typical piece of plastic, with a dash of antioxidant activity.

Credit: Adapted from ACS Applied Materials & Interfaces, 2022, DOI: 10.1021/acsami.2c05556

utensils and soda bottles, as well as medical devices, such as facial fillers and implants, now contain PLA. Just as lactic acid is a good building block for PLA, CBD’s chemical structure also has the right stuff to be re-

be made of CBD

Around the Area

UT Dallas

Robert A. Welch Chair in Chemistry, Dr. Vladimir Gevorgyan, gave a plenary talk, “New Heterocyclization and C H Functionalization Methods” at the Latvian Institute of Organic Synthesis’ Drug Discovery Conference in Riga. Cecil H. and Ida Green Distinguished Chair in Systems Biology, Dr. Dean Sherry, was presented the Harry Fischer Medal for lifetime contributions to the development of MRI contrast agents at the Contrast Media Research symposium in Annapolis.

From the ACS Press Room

Microneedle Patches that Restore Hair

Continued from page 5

Based on these results, the team prepared MnPS3 microneedle patches and treated androgenic alopecia affected mouse models with them. Within 13 days, the animals regenerated thicker hair strands that more densely covered their previously bald backsides than mice treated with testosterone or minoxidil. The researchers say that their study both produced a nanozyme treatment for regenerating hair, and indicated the potential for computer based methods for use in the design of future nanozyme therapeutics.

The authors acknowledge funding from the National Natural Science Foundation of China and the Natural Science Foundation of Shandong Province China.

Diagnose Alzheimer

’

s Disease Early

Continued from page 6

older subjects without the impairment. According to the researchers, no wellestablished biomarkers that can diagnose MCI currently exist. Thus, p tau198 and p tau217 could help clinicians intervene early, as new treatments become available, before significant neurological damage occurs. In addition, the researchers say this

From the ACS Press Room

method could be used to find tau biomarkers with other modifications aside from phosphorylation.

The authors acknowledge funding from the Biomarkers Across Neurodegenerative Diseases Program of the Alzheimer’s Association, Alzheimer’s Research UK, The Michael J. Fox Foundation for Parkinson’s Research, the Weston Brain Institute; Duke Clinical & Translational Science Institute; the National Institutes of Health; the Commonwealth of Virginia’s Alzheimer’s and Related Diseases Research Award Fund; Diabetes Action Research and Education Foundation; and the Duke/UNC Alzheimer’s Disease Research Center.

The authors have filed a provisional patent on the work.

Clear Window Coating

Continued from page 7

with conventional windows. They note their findings could be applied to other applications, since TRCs could also be used on car and truck windows. In addition, the group’s quantum computing enabled optimization technique could be used to design other types of composite materials.

The authors acknowledge support from the National Research Foundation of Korea and the Notre Dame Center for Research Computing.

Intranasal COVID Vaccine

Continued from page 8

the new vaccine were exposed to live virus, however, they still developed an infection. In contrast, intranasal coadministration in hamsters produced a strong systemic immune response. It also cleared viruses from the respiratory tract and prevented infection associated lung damage. Regardless of how the vaccine was administered, it provided protection against multiple variants, including omicron. Based on these results, the researchers are now recruiting participants for a Phase 1 clinical trial.

The authors acknowledge funding by the National Health Innovation Centre Gap Funding Award Singapore.

Mystery of What’s Coating Stradivari’s Violins

Continued from page 9

instruments contained protein-based compounds, congregating in nano sized patches. Because IR s SNOM provided a detailed 3D picture of the types of substances on the violin’s surface, the researchers say that it could be used in future studies to identify compounds in complex multi layer cultural heritage samples.

The authors acknowledge CERIC ERIC and Elettra Sincrotrone Trieste for access to experimental facilities and financial support.

From the ACS Press Room

Why Plastics Turn Yellow

Continued from page 10

films. The team concluded that chiral chemical structures on the surfaces of the polyethylene films are formed during exposure to UV light and are a potential cause for the yellow color of old plastics. They say that these insights could help researchers design plastic products that last longer before becoming unsightly or unusable.

The authors acknowledge funding from the University of Minnesota, Duluth, the University of Minnesota McKnight Foundation, and the U.S. Department of Energy.

Your Medical Implant or Food Wrapper could

Someday be made of CBD

Continued from page 11

peated as a polymer. So, Gregory Sotzing, Lakshmi Nair and colleagues wanted to see whether CBD could be used to make a new bioplastic.

To create cannabinoid polymers, the researchers performed a condensation reaction with adipoyl chloride also used to create nylon and either CBD or the closely-related cannabigerol (CBG), producing a polyester. Polymeric CBD had a broad melting temperature range and stretchability, and to show its ability to function as a plastic, the researchers formed it into a hemp leaf shape with a mold. Because bioplastics are often used in medical contexts, they also investigated the polymers’ bioactive properties. Neither CBD nor CBG polyesters was cytotoxic. Unlike the conventional bioplastic PLA, the CBD polyester had an antioxidant activity. Although the polymer version of CBD didn’t confer the same therapeutic effects as it does in oil form, Sotzing says that future versions of the plastic could be engineered to have anti inflammatory and pain relieving properties, and this is the goal of his start up company Polycannabinoid Therapeutics Rx.

The authors acknowledge funding from the National Institutes of Health for the biological aspects of this work.

From the Editor

Last week was the ACS Southwest Regional Meeting (fondly known as SWRM 2022) in Baton Rouge. It was held in the Hilton Hotel on Lafayette St., formerly the Heidelberg/Capitol House Hotels, favorite haunt of Huey P. Long in the ‘30s. The Heidelberg was also the site of 29th SW RegionalACS Meeting in 1972, the meeting at which I presented my first scientific paper: The effect of various pesticides and related compounds on crystalline rabbit muscle lactic dehydrogenase, with J. Bowden and R. S. Allen. As I stood up to go to the podium (this pre-dated poster sessions), in strolled three of my undergrad professors from Louisiana Tech. Aargh! I managed not to faint and gave the talk…and yes, that was fifty years ago, little though I like to think it. Time flies when you’re having fun!

Thanks to the LSU chemistry department who organized this SWRM. (I think the logo is a fleur de lis molecule…?)