ACS Chemistry for Life

Nuclear energy rebirth sparks growth in advanced materials
Chemical & Engineering News

An upsurge of interest in nuclear power as an energy source in the era of global climate change is fostering development of a new generation of supermaterials to ensure the safety and reliable performance of tomorrow’s nuclear power stations. C&EN senior editor Mitch Jacoby notes that the 1979 Three Mile Island nuclear accident, combined with economic factors, led the electric utility industry to stop submitting new applications for nuclear power plants. The U. S. Nuclear Regulatory Commission (NRC) got zero applications in the 30 years after Three Mile Island, but now the NRC’s construction permit inbox is filling up again, thanks in part to a growing interest in energy sources that do not emit carbon dioxide, the main greenhouse gas. In just the past two years, NRC has received applications for 28 new nuclear power plants, the article notes. These will incorporate new designs that improve safety and performance, and require advanced materials that can withstand higher temperatures and more intense radiation, according to the article. Scientists are developing a variety of promising candidates, including novel types of steels and alloys as well as metals and ceramic composites made with nanoparticles.

Home washing machines: Source of potentially harmful ocean “microplastic” pollution
Environmental Science & Technology

Mark Browne and colleagues are reporting that household washing machines seem to be a major source of so-called “microplastic” pollution – bits of polyester and acrylic smaller than the head of a pin – that they now have detected on ocean shorelines worldwide, raising health and safety concerns. The bits of plastic contain potentially harmful ingredients which go into the bodies of animals and could be transferred to people who consume fish. The scientists looked for microplastic contamination along 18 coasts around the world and did some detective work to track down a likely source of this contamination. They found more microplastic on shores in densely populated areas, and identified an important source – wastewater from household washing machines. They point out that more than 1,900 fibers can rinse off of a single garment during a wash cycle, and these fibers look just like the microplastic debris on shorelines. The problem, they say, is likely to intensify in the future, and the report suggests solutions: “Designers of clothing and washing machines should consider the need to reduce the release of fibers into wastewater and research is needed to develop methods for removing microplastic from sewage.”

A breath-takingly simple test for human exposure to potentially toxic substances
Environmental Science & Technology

The search for a rapid, non-invasive way to determine whether people have been exposed to potentially toxic substances in their workplaces, homes and elsewhere in the environment has led scientists to a technology that literally takes a person’s breath away. Andrea M. Dietrich, Masoud Agah, and their students Heather Vereb and Bassam Alfeeli explain that scientists have known since the late 1970s that exhaled breath contains traces of any potentially toxic substances that people may have inhaled. Research has shown that those amounts are an accurate reflection of the levels that exist in a person’s blood. Those advances have positioned exhaled breath as the ideal substance to use in rapid, non-invasive, simple testing for human exposure to potentially harmful substances in the air. Advances in microelectronics have helped position breath analysis for more extensive use in the 21^st century — equipment for analyzing substances in human breath that once had to be housed in laboratories, for instance, have shrunk to hand-held size. The technology can detect minute amounts of substances in the breath and do so quickly – offering the promise of helping limit human exposure and improve health.

Recycling thermal cash register receipts contaminates paper products with BPA
Environmental Science & Technology

Bisphenol A (BPA) – a substance that may have harmful health effects – occurs in 94 percent of thermal cash register receipts, scientists are reporting, and the recycling of those receipts, they add, is a source of BPA contamination of paper napkins, toilet paper, food packaging and other paper products. Kurunthachalam Kannan and Chunyang Liao explain that manufacturers produce more than 8 billion pounds of BPA worldwide every year. To see whether BPA on register receipts was a concern, the researchers analyzed hundreds of samples and 14 other types of paper products from the U.S., Japan, Korea and Vietnam. The only receipts that were BPA-free were those from Japan, which phased out this use of BPA in 2001. BPA on receipts is responsible for more than 98 percent of consumer exposure to BPA from paper. They note that handling of paper products can contribute up to 2 percent of the total daily BPA exposures in the general population, and that fraction can be much higher in occupationally exposed individuals.

Good news plus lingering concerns for Deepwater Horizon cleanup workers
Chemical & Engineering News

Several new studies of air and water near the site of the Deepwater Horizon oil spill conclude that cleanup workers may have escaped harm from one of the most worrisome groups of potentially toxic substances in the oil, but it cites concerns that another group of potentially harmful chemicals did escape from the water and could create a health hazard for cleanup workers. C&EN Senior Editor Elizabeth Wilson describes research showing that benzene, toluene, ethylbenzene, and xylene – collectively termed BTEX – remained dissolved in the Gulf of Mexico, and did not vaporize into the air where they could be inhaled by cleanup workers. Tempering that apparent good news for the health of cleanup workers, however, are concerns that other substance released by the crude oil, substances that do not dissolve as well in water, did become airborne during the 2010 disaster. If so, they could pose a health threat to cleanup workers, the article notes.

Laser beam makes cells “breathe in” water and potentially anti-cancer drugs
The Journal of Physical Chemistry Letters

Shining a laser light on cells and then clicking off the light-makes the cells “breathe in” surrounding water, providing a potentially powerful delivery system for chemotherapy drugs, as well as a non-invasive way to target anti-Alzheimer’s medicines to the brain. Andrei Sommer’s group, with Emad Aziz and colleagues note using this technique before to force cancer cells to sip up anti-cancer drugs and fluorescent dyes. Using the so-called Liquidrom ambient approach, developed by Aziz’s group, the researchers combined for the first time laser irradiation with soft X-rays obtained from a cyclotron radiation source to explore the molecular structure of interfacial water layers under ambient conditions. The researchers showed that laser light aimed at a cell causes the water inside the cell to expand. When the light goes off, the volume of water collapses again, creating a strong pull that also sucks in the water surrounding the cell. This “breathing in and out” of the water molecules can pull chemotherapy drugs into a cell faster than they would normally penetrate, the researchers found.

Turning up the heat to kill cancer cells: “The Lance Armstrong effect”
Molecular Pharmaceutics

Robert Getzenberg and Donald Coffey note that patients with testicular cancer have a high survival rate – more than 70 percent – even if the cancer metastasizes, or spreads. For example, Lance Armstrong, the famous cyclist, beat metastatic testicular cancer that spread to his lungs and brain, and then went on to win the Tour de France a record seven consecutive times. But patients with pancreatic cancer have only a 25 percent survival rate in the first year and a 6 percent survival rate by the fifth year after diagnosis. Testicles are usually several degrees cooler than the rest of the body, owing to their position outside the body. When cancer cells from the testicles spread to other organs, such as the lungs or brain, they encounter a warmer environment. The researchers propose that this warmth shocks the tumor cells, making them more susceptible to conventional cancer therapies, which leads to a higher survival rate among testicular cancer patients, the so-called “Lance Armstrong effect.” The researchers describe tests now underway on nanoparticle therapies to specifically heat other types of tumors above their normal temperatures to see whether this effect holds true for non-testicular cancers.

New tool to help surgeons remove more cancer tissue during brain surgery
Analytical Chemistry

Zoltán Takáts and colleagues are reporting development and successful initial testing of a new tool that tells whether brain tissue is normal or cancerous while an operation is underway, so that surgeons can remove more of the tumor without removing healthy tissue, improving patients’ survival. Cancer can recur if tumor cells remain in the body after surgery, so as a precaution, surgeons typically remove extra tissue surrounding a breast, prostate and other tumors in the body. But neurosurgeons face severe limitations because removing extra tissue can impair the patient’s memory, mobility and other vital functions. Current methods to precisely identify tumor margins take too long and are unreliable. To overcome these challenges, the researchers developed a new tool that can identify the margin between cancerous and healthy tissue in half the time previously needed. They describe linking a mainstay surgical tool termed an ultrasonic aspirator – used to break up and suction tissue – to a modified version of a standard laboratory tool called a mass spectrometer.

Giant Fire-Bellied Toad’s brain brims with powerful germ-fighters
Journal of Proteome Research

Ren Lai and colleagues point out that scientists know little about the germ-fighting proteins in amphibian brains, despite many studies showing that amphibians synthesize and secrete a remarkably diverse array of antimicrobial substances in their skin. So they decided to begin filling that knowledge gap by analyzing brains from the Giant Fire-Bellied Toad and the Small-webbed Bell Toad. They discovered 79 different antimicrobial peptides, the components of proteins, including 59 that were totally new to scientists. Some of the peptides showed strong antimicrobial activity, crippling or killing strains of staph bacteria, E. coli, and the fungus that causes yeast infections in humans. These promising findings suggest that the toad brains might be a valuable source for developing new antibacterial and antiviral drugs.

Simple chemical cocktail shows first promise for limb re-growth in mammals
ACS Chemical Biology

Darren R. Williams and Da-Woon Jung are reporting that a simple chemical cocktail can coax mouse muscle fibers to become the kinds of cells found in the first stages of a regenerating limb. It is the first demonstration that mammal muscle can be turned into the biological raw material for a new limb. The scientists describe the chemical cocktail that they developed and used to turn mouse muscle fibers into muscle cells. Williams and Jung then converted the muscle cells into fat and bone cells. Those transformations were remarkably similar to the initial processes that occur in the tissue of newts and salamanders that are starting to regrow severed limbs. In the future, they suggest, the chemicals they use could speed wound healing by providing new cells at the injured site before the wound closes or becomes infected, and their methods might also shed light on new ways to switch adult cells into the all-purpose, so-called “pluripotent,” stem cells with the potential for growing into any type of tissue in the body.

Mussel adhesive inspires tough coating for living cells
Journal of the American Chemical Society

Inspired by Mother Nature, scientists are reporting development of a protective coating with the potential to enable living cells to survive in a dormant state for long periods despite intense heat, dryness and other hostile conditions. Insung S. Choi and colleagues liken the coating to the armor that encloses the spores that protect anthrax and certain other bacterial cells, making those microbes difficult to kill. They say their simple method for coating the yeast cells could “serve as a new strategy for controlling cell division and protection of artificial spore like structures in a designed way.” The new coating is an organic material called polydopamine, chemically similar to mussel adhesive. In laboratory experiments, the coating slowed down cell division in the yeast, while protecting them from cell-digesting chemicals. The technique could be used to encapsulate individual cells for a variety of purposes, including the creation of tiny chemical probes, single-cell chemical factories, and perhaps armor for transplanted cells used in anti-cancer therapies.

Controversy over reopening the “Sistine Chapel” of Stone Age art
Chemical & Engineering News

Carmen Drahl, C&EN associate editor notes that Spanish officials closed Spain’s Altamira caves to the public in 2002 after scientists realized that visitors were fostering growth of bacteria that damage the paintings. Moisture and carbon dioxide from tourists’ breath, body heat and footsteps (which kick up bacterial spores) foster growth of bacteria on the cave walls. Those bacteria damage the precious wall paintings, which supposedly influenced great modern artists like Picasso. Now, however, they plan to reopen the caves. Declared a World Heritage Site by the United Nations’ Educational, Scientific and Cultural Organization (UNESCO), Altamira’s rock paintings of animals and human hands made scientists realize that Stone Age people had intellectual capabilities far greater than previously believed. Drahl discusses the scientific controversy over limited reopening of the caves to tourism and measures that could minimize further damage to the painting.

At long last, new plastics for baby bottles, shopping bags, and much more
Chemical & Engineering News

With most of the plastics that define modern life dating to the1930s-1960s, a new breed of these ubiquitous materials are starting to gain a foothold in products ranging from teapots to potato chip bags to plastic plant pots that biodegrade right in the soil. C&EN Senior Editor Alexander H. Tullo explains that a “golden age of polymers,” spanning the late 1930s through the mid-1960s, engendered nylon, polyethylene, polypropylene, polycarbonate, polyester, and other plastics that have replaced everything from silk to steel in everyday products. With that success, manufacturers were reluctant to switch to new and untested plastics, and companies that tried to introduce innovative polymers faced an Everest-like-landscape of hurdles. Now a new genre of plastics is overcoming those barriers. Among them is a new plastic with the crystal-clear clarity, toughness, resistance to heat, and other advantages needed to compete with polycarbonate. Made without the worrisome bisphenol A (BPA), it is replacing polycarbonate in baby bottles and beverage bottles. Another new plastic has potential for fighting global warming, consisting of 40 per cent carbon dioxide, the main greenhouse gas.