The botanical world can be an exciting place for chemists. Plant species produce a beautiful array of organic molecules with complex structures, often of great practical use. Indeed, this is a realm where new discoveries are still being made. Recently, a Japanese-led research team discovered an entirely new structural class in compounds from a jungle-dwelling shrub.
The glossy or red-fruited laurel (binomial name: Cryptocarya laevigata) inhabits the rainforests of eastern Australia. Little was known about the chemical makeup of this tall shrub until the team, led by Kanazawa University, analyzed an extract of its twigs and leaves. The plant’s essential oil was found to contain a family of six new compounds, the structural analysis of which revealed some surprises.
As reported in Organic Letters, NMR experiments showed that at the center of the compounds lay a peculiar, nine-membered carbon cycle known as a spiro-nonene. This structure consists of two rings of carbon atoms—one containing six atoms, the other four—linked by a single “pinch point” atom that is a part of both rings. This motif had never been seen before in any natural product.
New research from engineers at MIT shows that reconstituted silk can be several times stronger than the natural fiber and made in different forms.
When it comes to concocting the complex mix of molecules that makes up fibers of natural silk, nature beats human engineering hands down. Despite efforts to synthesize the material, artificial varieties still cannot match the natural fiber’s strength.
But by starting with silk produced by silkworms, breaking it down chemically, and then reassembling it, engineers have found they can make a material that is more than twice as stiff as its natural counterpart and can be shaped into complex structures such as meshes and lattices.
The new material is dubbed regenerated silk fiber (RSF) and could find a host of applications in commercial and biomedical settings, the researchers say. The findings are reported in the journal Nature Communications, in a paper by McAfee Professor of Engineering Markus Buehler, postdoc Shengjie Ling, research scientist Zhao Qin, and three others at Tufts University.
Brian Wagner, a chemistry professor at the University of Prince Edward Island, often works with fluorescent detector molecules in his lab. But instead of showing off his research, he decided to show off the fluorescent objects people interact with all the time by putting them under a 350-nm-wavelength ultraviolet lamp. From left to right, the substances shown are as follows: *Olive oil (contains various fluorescent compounds)
*Vitamin B-2, a.k.a. riboflavin, dissolved in water
*Turmeric dissolved in water (contains the fluorescent molecule curcumin)
*A bar of Irish Spring Original soap (contains the fluorescent molecule pyranine)
*Canola oil (contains various fluorescent compounds)
*Tonic water (contains the fluorescent molecule quinine)
Plastics are among the most successful materials of modern times. However, they also create a huge waste problem. Scientists from the University of Groningen (The Netherlands) and the East China University of Science and Technology (ECUST) in Shanghai produced different polymers from lipoic acid, a natural molecule. These polymers are easily depolymerized under mild conditions. Some 87 percent of the monomers can be recovered in their pure form and re-used to make new polymers of virgin quality. The process is described in an article that was published in the journal Matter on 4 February.
A problem with recycling plastics is that it usually results in a lower-quality product. The best results are obtained by chemical recycling, in which the polymers are broken down into monomers. However, this depolymerization is often very difficult to achieve. At the Feringa Nobel Prize Scientist Joint Research Center, a collaboration between the University of Groningen and ECUST, scientists developed a polymer that can be created and fully depolymerized under mild conditions.
Researchers at The University of Queensland, New Zealand, and the University of Münster, Germany, have gained insight into the photosynthesis process at a molecular level through understanding the cyclic electron flow supercomplex, which is a critical part of the photosynthetic machinery in plants. The discovery could help guide the development of next-generation solar biotechnologies.
The team purified and characterised the cyclic electron flow supercomplex from micro-algae, and analysed its structure using electron microscopy. The analysis showed how complexes that harvest light become supercomplexes that allow the plant to adapt to varying light conditions and energy requirements.
‘The cyclic electron flow supercomplex is an excellent example of an evolutionarily highly conserved structure,’ says Professor Hippler, the University of Münster. ‘By the year 2050, we will need 50% more fuel, 70% more food, and 50% more clean water. Technologies based on photosynthetic microalgae have the potential to play an important role in meeting these needs’, says Professor Ben Hankamer of the University of Queensland.
The discovery will help guide the design of next generation solar capture technologies based on micro-algae and a wide range of solar driven biotechnologies. This can help produce food, fuel and clean water.
The complex architecture of bone is challenging to recreate in the lab. Therefore, advances in bone tissue engineering (BTE) aim to build patient-specific grafts that assist bone repair and trigger specific cell-signaling pathways. Materials scientists in regenerative medicine and BTE progressively develop new materials for active biological repair at a site of defect post-implantation to accelerate healing through bone biomimicry.
Rapidly initiation of new bone formation at the site of implantation is a highly desirable feature in BTE, and scientists are focused on fabricating grafts that strengthen the material-bone interface after implantation. Bioactive glass can bond with bone minutes after grafting, and silk fibroin, a natural fibrous protein has potential to induce bone regeneration. Hybrid materials that exploit these properties can combine the osteogenic potential and the load-bearing capacity for potential applications in large-load bone defect models.
In a recent study, Swati Midha and co-workers developed a novel 3-D hybrid construct using silk-based inks with different bioactive glass compositions integrated to recreate a bone-mimetic microenvironment that supports osteogenic differentiation of bone marrow mesenchymal stem cell (BMSC) lines in the lab. Now published in Biomedical Materials, IOP Science, the scientists used direct writing instruments to produce the silk fibroin-gelatin-bioactive glass scaffolds (SF-G-BG). The results delivered appropriate cues to regulate the development of customized 3-D human bone constructs in vitro.
In a microscopic feat that resembled a high-wire circus act, Johns Hopkins researchers have coaxed DNA nanotubes to assemble themselves into bridge-like structures arched between two molecular landmarks on the surface of a lab dish.
The team captured examples of this unusual nanoscale performance on video.
This self-assembling bridge process, which may someday be used to connect electronic medical devices to living cells, was reported by the team recently in the journal Nature Nanotechnology.
To describe this process, senior author Rebecca Schulman, an assistant professor of chemical and biomolecular engineering in the university’s Whiting School of Engineering, referred to a death-defying stunt shown in the movie “Man on Wire.” The film depicted Philippe Petit’s 1974 high-wire walk between the World Trade Center’s Twin Towers.
Schulman pointed out that the real-life crossing could not have been accomplished without a critical piece of old-fashioned engineering: Petit’s hidden partner used a bow and arrow to launch the wire across the chasm between the towers, allowing it to be secured to each structure.
Porphyrins, the same molecules that convey oxygen in hemoglobin and absorb light during photosynthesis, can be joined to the material of the future, graphene, to give it new properties. This was recently shown by a team of scientists at the Technical University of Munich, in which a Spanish researcher also participated. The resulting hybrid structures could be used in the field of molecular electronics and in developing new sensors.
At the moment, it is difficult to find a material that attracts as much attention from scientists and engineers as graphene, which is made up of a layer of carbon atoms arrange in a hexagonal structure. It is flexible, extremely thin and clear, while being highly resistant and a conductor of electricity – ideal requirements for a number of uses, especially in the field of electronics.
However, using graphene to capture solar energy or as a gas sensor requires specific properties which it lacks, although it can acquire them by addition or functionalisation with certain molecules.
A team of researchers from the Technical University of Munich (TUM), led by Professor Wilhelm Auwärter, has succeeded in bonding an important biochemical group to the graphene sheet: porphyrins, protein rings which are part of chlorophyll, essential for photosynthesis in plants, and hemoglobin, which is responsible for conveying oxygen in animals’ blood.
A team of researchers led by Biomedical Engineering Professor Sam Sia at Columbia Engineering has developed a way to manufacture microscale-sized machines from biomaterials that can safely be implanted in the body. Working with hydrogels, which are biocompatible materials that engineers have been studying for decades, Sia has invented a new technique that stacks the soft material in layers to make devices that have three-dimensional, freely moving parts. The study, published online January 4, 2017, in Science Robotics, demonstrates a fast manufacturing method Sia calls “implantable microelectromechanical systems” (iMEMS).
By exploiting the unique mechanical properties of hydrogels, the researchers developed a “locking mechanism” for precise actuation and movement of freely moving parts, which can provide functions such as valves, manifolds, rotors, pumps, and drug delivery. They were able to tune the biomaterials within a wide range of mechanical and diffusive properties and to control them after implantation without a sustained power supply such as a toxic battery. They then tested the “payload” delivery in a bone cancer model and found that the triggering of release of doxorubicin from the device over 10 days showed high treatment efficacy and low toxicity, at 1/10 of the standard systemic chemotherapy dose.
Combining bacterial genes, virus shell creates a highly efficient, renewable material used in generating power from water
Scientists at Indiana University have created a highly efficient biomaterial that catalyzes the formation of hydrogen – one half of the “holy grail” of splitting H2O to make hydrogen and oxygen for fueling cheap and efficient cars that run on water.
A modified enzyme that gains strength from being protected within the protein shell – or “capsid” – of a bacterial virus, this new material is 150 times more efficient than the unaltered form of the enzyme.
The process of creating the material was recently reported in “Self-assembling biomolecular catalysts for hydrogen production” in the journalNature Chemistry.
“Essentially, we’ve taken a virus’s ability to self-assemble myriad genetic building blocks and incorporated a very fragile and sensitive enzyme with the remarkable property of taking in protons and spitting out hydrogen gas,” said Trevor Douglas, the Earl Blough Professor of Chemistry in the IU Bloomington College of Arts and Sciences’ Department of Chemistry, who led the study. “The end result is a virus-like particle that behaves the same as a highly sophisticated material that catalyzes the production of hydrogen.”
High-Tech Wood: Research Unlocks Unexpected Products from Trees
by Michael Keller
The 21st century tree farm isn’t going to offer just the raw materials for paper, buildings and furniture. Technologies are starting to unlock new uses for trees–for biofuels, new chemicals and a product called nanocellulose, a carbohydrate building block of plants that might just be the next supermaterial.
It turns out that trees have been deploying their own nanotechnology for millennia, growing nanocellulose as a major component of their trunks for strength and to resist wind and rain while minimizing weight. Individual particles are less than a thousandth the width of a sand grain–generally less than 500 nanometers long and 20 nanometers wide. After it has been processed from wood pulp using high temperature and pressure to liberate it, the material is light, stiff and strong, is biodegradable and is cheaper to produce than many advanced products developed in a lab. It also exhibits highly sought-after properties.
Because it can add strength to materials in small enough quantities that allows light to pass through, the Army is looking at it as an additive for durable transparent composites. Others are investigating its use in applications from biocompatible implants and flexible displays and solar panels to better bioplastics, cosmetics and concrete. See a picture and learn more below.
Spider silk has long been noted for its graceful structure, as well as its advanced material properties: Ounce for ounce, it is stronger than steel. Scientists at MIT have developed a systematic approach to research the structure of spider silk, blending computational modeling and mechanical…
Often, the findings of fundamental scientific research are many steps away from a product that can be immediately brought to the public. But every once in a while, opportunity makes an early appearance.
Such was the case for a team from the Department of Energy’s Joint BioEnergy Institute (JBEI), whose outside-the-box thinking when investigating microbe-based biomanufacturing led straight to an eco-friendly production platform for a blue pigment called indigoidine. With a similar vividly saturated hue as synthetic indigo, a dye used around the world to color denim and many other items, the team’s fungi-produced indigoidine could provide an alternative to a largely environmentally unfriendly process.
“Originally extracted from plants, most indigo used today is synthesized,” said lead researcher Aindrila Mukhopadhyay, who directs the Host Engineering team at JBEI. “These processes are efficient and inexpensive, but they often require toxic chemicals and generate a lot of dangerous waste. With our work we now have a way to efficiently produce a blue pigment that uses inexpensive, sustainable carbon sources instead of harsh precursors. And so far, the platform checks many of the boxes in its promise to be scaled-up for commercial markets.”
Artificial muscles made from polymers can now be powered by energy from glucose and oxygen, just like biological muscles. This advance may be a step on the way to implantable artificial muscles or autonomous microrobots powered by biomolecules in their surroundings. Researchers at Linköping University, Sweden, have presented their results in the journal Advanced Materials.
The motion of our muscles is powered by energy that is released when glucose and oxygen take part in biochemical reactions. In a similar way, manufactured actuators can convert energy to motion, but the energy in this case comes from other sources, such as electricity. Scientists at Linköping University, Sweden, wanted to develop artificial musclesthat act more like biological muscles. They have now demonstrated the principle using artificial muscles powered by the same glucose and oxygen as our bodies use.
The researchers have used an electroactive polymer, polypyrrole, which changes volume when an electrical current is passed. The artificial muscle, known as a “polymer actuator,” consists of three layers: a thin membrane layer between two layers of electroactive polymer. This design has been used in the field for many years. It works when the material on one side of the membrane acquires a positive electrical charge and ions are expelled, causing it to shrink. At the same time, the material on the other side acquires a negative electrical charge and ions are inserted, which causes the material to expand. The changes in volume cause the actuator to bend in one direction, in the same way that a muscle contracts.
Insect infestation is becoming an increasingly costly problem to the forestry industry, especially in areas experiencing increased droughts and hot spells related to climate change. A new terahertz imaging technique could help slow the spread of these infestations by detecting insect damage inside wood before it becomes visible on the outside.
“Our approach could be used to detect early-stage insect infestation on the trunks of trees, in imported wood or on wood products in an early infestation stage,” said research team member Kirsti Krügener, from HAWK University of Applied Science and Arts in Germany. “This could help keep out damaging insects from other countries and stop infestation before it spreads throughout a forest.”
In the Optical Society journal Applied Optics, the researchers report how they used terahertz time-of-flight tomography to noninvasively identify wood samples with otherwise invisible damage from the typographer beetle, which infects spruce and other coniferous trees in Europe. They were also able to reconstruct the internal structure of wood samples.
“Detecting the boreholes of wood-destroying insects is typically done by manually inspecting the wood, and the infected area of the forest to be removed is then estimated,” said Krügener. “To our knowledge, this is the first time a technical method has been used to detect insect boreholes.”
A new mathematical model describes how highly concentrated antibody solutions separate into different phases, similar to an oil and water mixture. This separation can reduce the stability and shelf-life of some drugs that use monoclonal antibodies, including some used to treat autoimmune diseases and cancer. A team of scientists from Penn State and MedImmune, LLC (now AstraZeneca) investigated the thermodynamics and kinetics, the relationships between temperature, energy, and the rates of chemical reactions, of the phenomenon using an innovative method that allows for the rapid study of multiple samples at once. A paper describing their model appears July 22, 2019, in the journal Proceedings of the National Academy of Sciences.
Many drugs today are stored as solids and dissolved in IV bags for delivery to patients, but the pharmaceutical industry has been moving toward drugs that can be stored as liquids and given via a shot. Some of these drug solutions, like those used to treat autoimmune diseases and some cancers, contain high concentrations of monoclonal antibodies—proteins that attach to foreign substances in the body, like bacteria and viruses, flagging them for destruction by the patient’s immune system.
The research team of Dr. Jae-woo Choi and Dr. Kyung-won Jung of the Korea Institute of Science and Technology’s (KIST, president: Byung-gwon Lee) Water Cycle Research Center announced that it has developed a wastewater treatment process that uses a common agricultural byproduct to effectively remove pollutants and environmental hormones, which are known to be endocrine disruptors.
The sewage and wastewater that are inevitably produced at any industrial worksite often contain large quantities of pollutants and environmental hormones (endocrine disruptors). Because environmental hormones do not break down easily, they can have a significant negative effect on not only the environment but also the human body. To prevent this, a means of removing environmental hormones is required.
The performance of the catalyst that is currently being used to process sewage and wastewater drops significantly with time. Because high efficiency is difficult to achieve given the conditions, the biggest disadvantage of the existing process is the high cost involved. Furthermore, the research done thus far has mostly focused on the development of single-substance catalysts and the enhancement of their performance. Little research has been done on the development of eco-friendly nanocomposite catalysts that are capable of removing environmental hormones from sewage and wastewater.
The KIST research team, led by Dr. Jae-woo Choi and Dr. Kyung-won Jung, utilized biochar, which is eco-friendly and made from agricultural byproducts, to develop a wastewater treatment process that effectively removes pollutants and environmental hormones. The team used rice hulls, which are discarded during rice harvesting, to create a biochar** that is both eco-friendly and economical. The surface of the biochar was coated with nano-sized manganese dioxide to create a nanocomposite. The high efficiency and low cost of the biochar-nanocomposite catalyst is based on the combination of the advantages of the biochar and manganese dioxide.
A University of Alberta researcher has found a new use for a canola byproduct, providing potential for diverse markets beyond China.
Canolastraw—the fibrous stalk left in the field after the plant is harvested for its oil—is proving useful in strengthening a plant-based cling wrap developed by Marleny Saldaña, a researcher in food and bioengineering processing.
In a new study, Saldaña and her research team used cellulose nanofibres from canolastraw to make the clear, plastic-like film, which is 12 times stronger than what they’ve already developed from cassava starch. The straw, which has little other use except as bedding for soil nutrients, contains cellulose and lignin, two components that support the canola plant.
Using canola straw this way demonstrates potential value-added options for the crop residue besides obtaining oil and protein from its seed, said Saldaña, who believes her and her team’s discovery to be the first application of its kind.
An international research team has used the X-ray laser European XFEL to gain new insights into how radiation damage occurs in biological tissue. The study reveals in detail how water molecules are broken apart by high-energy radiation, creating potentially hazardous radicals and electrically charged ions, which can go on to trigger harmful reactions in the organism. The team led by Maria Novella Piancastelli and Renaud Guillemin from the Sorbonne in Paris, Ludger Inhester from DESY and Till Jahnke from European XFEL is presenting its observations and analyses in the scientific journal Physical Review X.
Sincewater is present in every known living organism, the splitting of the water molecule H2O by radiation, called the photolysis of water, is often the starting point for radiation damage. “However, the chain of reactions that can be triggered in the body by high-energy radiation is still not fully understood,” explains Inhester. “For example, even just observing the formation of individual charged ions and reactive radicals in water when high-energy radiation is absorbed is already very difficult.”
To study this sequence of events, the researchers shot the intense pulses from the X-ray laser at the water vapor. Water molecules normally disintegrate on absorbing a single such high-energy X-ray photon. “Due to the particularly intense pulses from the X-ray laser, it was even possible to observe water molecules absorbing not just one, but two or even more X-ray photons before their debris flew apart,” Inhester reports. This gives the researchers a glimpse of what goes on inside the molecule after the first absorption of an X-ray photon.
