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News Article | May 17, 2017
Site: www.sciencedaily.com

Chemists, materials scientists and nanoengineers at UC San Diego have created what may be the ultimate natural sunscreen. In a paper published in the American Chemical Society journal ACS Central Science, they report the development of nanoparticles that mimic the behavior of natural melanosomes, melanin-producing cell structures that protect our skin, eyes and other tissues from the harmful effects of ultraviolet radiation. "Basically, we succeeded in making a synthetic version of the nanoparticles that our skin uses to produce and store melanin and demonstrated in experiments in skin cells that they mimic the behavior of natural melanosomes," said Nathan Gianneschi, a professor of chemistry and biochemistry, materials science and engineering and nanoengineering at UC San Diego, who headed the team of researchers. The achievement has practical applications. "Defects in melanin production in humans can cause diseases such as vitiligo and albinism that lack effective treatments," Gianneschi added. Vitiligo develops when the immune system wrongly attempts to clear normal melanocytes from the skin, effectively stopping the production of melanocytes. Albinism is due to genetic defects that lead to either the absence or a chemical defect in tyrosinase, a copper-containing enzyme involved in the production of melanin. Both of these diseases lack effective treatments and result in a significant risk of skin cancer for patients. "The widespread prevalence of these melanin-related diseases and an increasing interest in the performance of various polymeric materials related to melanin prompted us to look for novel synthetic routes for preparing melanin-like materials," Gianneschi said. Melanin particles are produced naturally in many different sizes and shapes by animals -- for iridescent feathers in birds or the pigmented eyes and skin of some reptiles. But scientists have discovered that extracting melanins from natural sources is a difficult and potentially more complex process than producing them synthetically. Gianneschi and his team discovered two years ago that synthetic melanin-like nanoparticles could be developed in a precisely controllable manner to mimic the performance of natural melanins used in bird feathers. "We hypothesized that synthetic melanin-like nanoparticles would mimic naturally occurring melanosomes and be taken up by keratinocytes, the predominant cell type found in the epidermis, the outer layer of skin," said Gianneschi. In healthy humans, melanin is delivered to keratinocytes in the skin after being excreted as melanosomes from melanocytes. The UC San Diego scientists prepared melanin-like nanoparticles through the spontaneous oxidation of dopamine -- developing biocompatible, synthetic analogues of naturally occurring melanosomes. Then they studied their update, transport, distribution and ultraviolet radiation-protective capabilities in human keratinocytes in tissue culture. The researchers found that these synthetic nanoparticles were not only taken up and distributed normally, like natural melanosomes, within the keratinocytes, they protected the skin cells from DNA damage due to ultraviolet radiation. "Considering limitations in the treatment of melanin-defective related diseases and the biocompatibility of these synthetic melanin-like nanoparticles in terms of uptake and degradation, these systems have potential as artificial melanosomes for the development of novel therapies, possibly supplementing the biological functions of natural melanins," the researchers said in their paper.


News Article | May 1, 2017
Site: www.chromatographytechniques.com

Chemiluminescence, or chemical light, is the principle behind glow sticks (also known as light sticks) used at rock concerts and as quick tools to grab when the electricity goes out. But they can also be used to diagnose diseases by identifying concentrations of biological samples. A new mechanism developed by Tel Aviv University researchers produces a 3,000-times-brighter, water-resistant chemiluminescent probe with particular application to medical and cancer diagnosis. The research found that tweaking the electronic structure of current probes improves their inherent fluorescence. This could lead to the invention of a new single-component system with multiple applications -- including the detection and measurement of cellular activity that points to certain pathologies, such as cancer. The study was recently published in ACS Central Science. "Chemiluminescence is considered one of the most sensitive methods used in diagnostic testing," said Doron Shabat of TAU's School of Chemistry, who led the research. "We have developed a method to prepare highly efficient compounds that emit light upon contact with a specific protein or chemical. These compounds can be used as molecular probes to detect cancerous cells, among other applications." The research, conducted in collaboration with Christoph Bauer of Geneva University, repairs an energy-loss "glitch" in current chemiluminescent probes. Most systems use a mixture of one emitter molecule that detects the species of interest, and another two additional ingredients -- a fluorophore and a soap-like substance called a surfactant -- that amplify the signal to detectable levels. But energy is lost in the transfer process from the emitter molecule to the fluorophore, and surfactants are not biocompatible. "As synthetic chemists, we knew how to link structure and function," said Shabat. "By adding two key atoms, we created a much brighter probe than those currently on the market. In addition, this particular molecule is suitable for direct use in cells." Based on this molecule, the researchers developed sensors to detect several biologically relevant chemicals. They also used the chemiluminescent molecule to measure the activity of several enzymes and to image cells by microscopy. "This gives us a new powerful methodology with which we can prepare highly efficient chemiluminescence sensors for the detection, imaging and analysis of various cell activities," said Shabat. The researchers are currently exploring ways of amplifying the chemiluminescence of the new probes for in vivo imaging.


News Article | May 1, 2017
Site: www.eurekalert.org

Chemiluminescence, or chemical light, is the principle behind the glow sticks (also known as light sticks) used at rock concerts and as quick tools to grab when the electricity goes out. But they can also be used to diagnose diseases by identifying concentrations of biological samples. A new mechanism developed by Tel Aviv University researchers produces a 3,000-times-brighter, water-resistant chemiluminescent probe with particular application to medical and cancer diagnosis. The research found that tweaking the electronic structure of current probes improves their inherent fluorescence. This could lead to the invention of a new single-component system with multiple applications -- including the detection and measurement of cellular activity that points to certain pathologies, such as cancer. The study was recently published in ACS Central Science. "Chemiluminescence is considered one of the most sensitive methods used in diagnostic testing," said Prof. Doron Shabat of TAU's School of Chemistry, who led the research. "We have developed a method to prepare highly efficient compounds that emit light upon contact with a specific protein or chemical. These compounds can be used as molecular probes to detect cancerous cells, among other applications." The research, conducted in collaboration with Dr. Christoph Bauer of Geneva University, repairs an energy-loss "glitch" in current chemiluminescent probes. Most systems use a mixture of one emitter molecule that detects the species of interest, and another two additional ingredients -- a fluorophore and a soap-like substance called a surfactant -- that amplify the signal to detectable levels. But energy is lost in the transfer process from the emitter molecule to the fluorophore, and surfactants are not biocompatible. "As synthetic chemists, we knew how to link structure and function," said Prof. Shabat. "By adding two key atoms, we created a much brighter probe than those currently on the market. In addition, this particular molecule is suitable for direct use in cells." Based on this molecule, the researchers developed sensors to detect several biologically relevant chemicals. They also used the chemiluminescent molecule to measure the activity of several enzymes and to image cells by microscopy. "This gives us a new powerful methodology with which we can prepare highly efficient chemiluminescence sensors for the detection, imaging and analysis of various cell activities," said Prof. Shabat. The researchers are currently exploring ways of amplifying the chemiluminescence of the new probes for in vivo imaging. The research was funded in part by the Israel Science Foundation, the Binational Science Foundation, the German Israeli Foundation, and the Israeli National Nanotechnology Initiative. American Friends of Tel Aviv University (AFTAU) supports Israel's most influential, comprehensive and sought-after center of higher learning, Tel Aviv University (TAU). TAU is recognized and celebrated internationally for creating an innovative, entrepreneurial culture on campus that generates inventions, startups and economic development in Israel. For three years in a row, TAU ranked 9th in the world, and first in Israel, for alumni going on to become successful entrepreneurs backed by significant venture capital, a ranking that surpassed several Ivy League universities. To date, 2,400 patents have been filed out of the University, making TAU 29th in the world for patents among academic institutions.


News Article | May 1, 2017
Site: phys.org

Image generated by the glow stick probe of cancerous cells. Credit: Prof. Doron Shabat/American Friends of Tel Aviv University (AFTAU) Chemiluminescence, or chemical light, is the principle behind the glow sticks (also known as light sticks) used at rock concerts and as quick tools to grab when the electricity goes out. But they can also be used to diagnose diseases by identifying concentrations of biological samples. A new mechanism developed by Tel Aviv University researchers produces a 3,000-times-brighter, water-resistant chemiluminescent probe with particular application to medical and cancer diagnosis. The research found that tweaking the electronic structure of current probes improves their inherent fluorescence. This could lead to the invention of a new single-component system with multiple applications—including the detection and measurement of cellular activity that points to certain pathologies, such as cancer. The study was recently published in ACS Central Science. "Chemiluminescence is considered one of the most sensitive methods used in diagnostic testing," said Prof. Doron Shabat of TAU's School of Chemistry, who led the research. "We have developed a method to prepare highly efficient compounds that emit light upon contact with a specific protein or chemical. These compounds can be used as molecular probes to detect cancerous cells, among other applications." The research, conducted in collaboration with Dr. Christoph Bauer of Geneva University, repairs an energy-loss "glitch" in current chemiluminescent probes. Most systems use a mixture of one emitter molecule that detects the species of interest, and another two additional ingredients—a fluorophore and a soap-like substance called a surfactant—that amplify the signal to detectable levels. But energy is lost in the transfer process from the emitter molecule to the fluorophore, and surfactants are not biocompatible. "As synthetic chemists, we knew how to link structure and function," said Prof. Shabat. "By adding two key atoms, we created a much brighter probe than those currently on the market. In addition, this particular molecule is suitable for direct use in cells." Based on this molecule, the researchers developed sensors to detect several biologically relevant chemicals. They also used the chemiluminescent molecule to measure the activity of several enzymes and to image cells by microscopy. "This gives us a new powerful methodology with which we can prepare highly efficient chemiluminescence sensors for the detection, imaging and analysis of various cell activities," said Prof. Shabat. The researchers are currently exploring ways of amplifying the chemiluminescence of the new probes for in vivo imaging. More information: Ori Green et al, Opening a Gateway for Chemiluminescence Cell Imaging: Distinctive Methodology for Design of Bright Chemiluminescent Dioxetane Probes, ACS Central Science (2017). DOI: 10.1021/acscentsci.7b00058


News Article | May 3, 2017
Site: phys.org

Researchers use fluorescence probes to monitor increases in mRNA-ribosome interaction levels for a gene associated with iron storage in response to iron (right panels). Scale bar = 20 μm. Credit: American Chemical Society Think of life as a house: if DNA molecules are blueprints, then messenger RNAs (mRNAs) are orders, describing the required parts (proteins) and when they should arrive. But putting in many orders doesn't always mean you'll get all of the parts on time—maybe there's a delay with your vendor or delivery service. Similarly, mRNA levels alone do not dictate protein levels. Today in ACS Central Science, researchers report a method to address that issue. David Tirrell, Kelly Burke and Katie Antilla note that in order to better understand how genes are regulated, one needs to see the mRNA when it is at the site of protein synthesis. Using fluorescence probes, the researchers designed a technique that shows mRNA when it comes in contact with giant protein synthesizing machines called ribosomes. They used this method to record the synthesis of proteins and to measure cellular responses to iron. Unlike previous methods, their tool works without the need to engineer an mRNA of interest. Tirrell notes that the method is applicable to essentially any type of RNA, and could be modified to visualize other types of interactions in the cell. Explore further: Researchers prove protein synthesis and mRNA degradation are structurally linked


News Article | May 3, 2017
Site: www.eurekalert.org

Think of life as a house: if DNA molecules are blueprints, then messenger RNAs (mRNAs) are orders, describing the required parts (proteins) and when they should arrive. But putting in many orders doesn't always mean you'll get all of the parts on time -- maybe there's a delay with your vendor or delivery service. Similarly, mRNA levels alone do not dictate protein levels. Today in ACS Central Science, researchers report a method to address that issue. David Tirrell, Kelly Burke and Katie Antilla note that in order to better understand how genes are regulated, one needs to see the mRNA when it is at the site of protein synthesis. Using fluorescence probes, the researchers designed a technique that shows mRNA when it comes in contact with giant protein synthesizing machines called ribosomes. They used this method to record the synthesis of proteins and to measure cellular responses to iron. Unlike previous methods, their tool works without the need to engineer an mRNA of interest. Tirrell notes that the method is applicable to essentially any type of RNA, and could be modified to visualize other types of interactions in the cell. The authors acknowledge funding from the National Science Foundation, Rose Hills Foundation, German Research Foundation and the Gordon and Betty Moore Foundation. The paper will be freely available on May 3 here: http://pubs. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies. Its main offices are in Washington, D.C., and Columbus, Ohio. To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.


News Article | May 2, 2017
Site: www.rdmag.com

A novelty glow stick might hold the key to detecting cancer and other diseases. Researchers from Tel Aviv University have developed a water-resistant chemiluminescent probe that can detect and measure cellular activity that points to certain pathologies, including cancer. The researchers were able to tweak the electronic structure of current probes to improve their inherent fluorescence, which could lead to the invention of a single component system with multiple application opportunities. “Chemiluminescence is considered one of the most sensitive methods used in diagnostic testing,” professor Doron Shabat of TAU’s School of Chemistry, who led the research, said in a statement. “We have developed a method to prepare highly efficient compounds that emit light upon contact with a specific protein or chemical. “These compounds can be used as molecular probes to detect cancerous cells, among other applications,” he added. The majority of systems use a mixture of one emitter molecule that detects the species of interest, as well as a fluorophore and a soap-like substance called a surfactant that amplify the signal to detectable levels. However, the researchers repaired an energy-loss “glitch” in current chemiluminescent probes. “As synthetic chemists, we knew how to link structure and function,” Shabat said. "By adding two key atoms, we created a much brighter probe than those currently on the market. In addition, this particular molecule is suitable for direct use in cells." The researchers developed sensors that detect several biologically relevant chemicals based on the molecule used and also used the chemiluminescent molecule to measure the activity of several enzymes and to image cells by microscopy. “This gives us a new powerful methodology with which we can prepare highly efficient chemiluminescence sensors for the detection, imaging and analysis of various cell activities,” Shabat said. According to the study, chemiluminescence probes are considered to be among the most sensitive diagnostic tools that provide high signal-to-noise ratio for various applications such as DNA detection and immunoassays. The next step for the researchers is to explore ways to amplify the chemiluminescence of the new probes for in vivo imaging. The study was published in ACS Central Science.


News Article | February 22, 2017
Site: www.eurekalert.org

Chemists at the University of Waterloo, SCIEX and Pfizer have discovered a new way to help the pharmaceutical industry identify and test new drugs, which could revolutionize drug development, and substantially reduce the cost and time drugs need to reach their market. The study, published in the journal ACS Central Science, outlines a technique called differential mobility spectrometry (DMS) which analyzes drug molecules based on their response to an electrical field and the condensation-evaporation cycles the drug experiences in that field via a process, known as microsolvation. "We can use this technique to measure drug properties in seconds to minutes with only nanograms of sample," says Scott Hopkins, a professor of chemistry at the University of Waterloo and corresponding author on the paper. "It's cost saving and high throughput, so you can test hundreds, even thousands of drugs quickly, increasing the rate of drug discovery." Currently drug candidates are put through a battery of tests to measure their chemical and physical properties, such as how easily the drug crosses cell membranes, to predict how it will behave in the human body. Drugs must perform within a specific range in order to move forward to clinical trials. Most drugs fail the initial stages resulting in lost time and money. "It takes time to grow cells and run replicate experiments to measure permeability," said Hopkins. "These kinds of assays are an arduous process, and the people that conduct this work are artists as well as scientists." In contrast, these essential physical and chemical properties can be extracted all at once with a single analysis using DMS. The technique is so sensitive it can differentiate between the same drug molecules with slightly different atomic structures - something traditional testing methods cannot do. "With this technology, the initial stages of drug development testing can be completed in hours rather than days," says Hopkins. "It's not only several orders of magnitude faster, it gives us information we never had access to before that we can use for rational drug design." Beyond improving the testing and design drugs go through, Hopkins is hopeful this technology will improve the success of candidate drugs being proposed in the first place by informing the design process.


News Article | February 22, 2017
Site: phys.org

The study, published in the journal ACS Central Science, outlines a technique called differential mobility spectrometry (DMS) which analyzes drug molecules based on their response to an electrical field and the condensation-evaporation cycles the drug experiences in that field via a process, known as microsolvation. "We can use this technique to measure drug properties in seconds to minutes with only nanograms of sample," says Scott Hopkins, a professor of chemistry at the University of Waterloo and corresponding author on the paper. "It's cost saving and high throughput, so you can test hundreds, even thousands of drugs quickly, increasing the rate of drug discovery." Currently drug candidates are put through a battery of tests to measure their chemical and physical properties, such as how easily the drug crosses cell membranes, to predict how it will behave in the human body. Drugs must perform within a specific range in order to move forward to clinical trials. Most drugs fail the initial stages resulting in lost time and money. "It takes time to grow cells and run replicate experiments to measure permeability," said Hopkins. "These kinds of assays are an arduous process, and the people that conduct this work are artists as well as scientists." In contrast, these essential physical and chemical properties can be extracted all at once with a single analysis using DMS. The technique is so sensitive it can differentiate between the same drug molecules with slightly different atomic structures - something traditional testing methods cannot do. "With this technology, the initial stages of drug development testing can be completed in hours rather than days," says Hopkins. "It's not only several orders of magnitude faster, it gives us information we never had access to before that we can use for rational drug design." Beyond improving the testing and design drugs go through, Hopkins is hopeful this technology will improve the success of candidate drugs being proposed in the first place by informing the design process. Explore further: Researchers use light to control human heart cells and expedite development of new drugs


Payments for ecosystem services (PES) have received considerable attention as a promising approach for correcting environmental externalities. Frequent shortcomings or outright lack of performance assessments of environmental interventions in general and PES projects in particular have resulted in recommendations for "optimal" PES designs. Conditionality-paying service providers only if services or proxy inputs are delivered-and targeting-allocating payments based on service gains, provision costs or both-are central to such recommendations. We argue that a) true economic optimality is an unattainable PES objective and improving PES cost-effectiveness is a more realistic aspiration, and that b) current PES programs actually prevent cost-effectiveness analyses because they lack appropriate ecosystem service definitions and thus output measurements. We review the effects of conditionality on service flows and provide a framework for identifying the cost-effective level of conditionality stringency. We identify key analytical methods, data and analysis tools required to improve the cost-effectiveness of PES-or any ecosystem service-projects. Needed analytical concepts, metrics, and monitoring and modeling approaches often are sufficiently available for PES design to begin incorporating them. What is missing is their coherent application. Improving spatial-analytical and monitoring capacities should allow gradual implementation of modifications needed to improve PES cost-effectiveness. © 2012 Elsevier B.V.

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