Scientists Develop Molecular Code for Melanin-Like Materials

NEW YORK, (June 8, 2017) – Scientists have long known that melanin—the pigments that give color to skin, hair and eyes—has numerous useful qualities, including providing protection from cancer-causing UV radiation and free radicals, but also electronic conductance, adhesiveness and the capacity to store energy.

To take advantage of these qualities, scientists across the City University of New York (CUNY) have developed a new approach for producing materials that not only mimic the properties of melanin, but also provide unprecedented control over expressing specific properties of the biopolymer, according to a paper published today in the journal Science. The discovery could enable the development of cosmetic and biomedical products.

Unlike other biopolymers, such as DNA and proteins, where a direct link exists between the polymers’ ordered structures and their properties, melanin is inherently disordered, so directly relating structure to function is not possible. As a result, researchers have been unable to fully exploit melanin’s properties because the laboratory-based synthesis of melanin has been thwarted by the difficulty of engineering its disorderly molecular structure.

“We took advantage of simple versions of proteins—tripeptides, consisting of just three amino acids—to produce a range of molecular architectures with precisely controlled levels of order and disorder,” said lead researcher Rein V. Ulijn, director of the Nanoscience Initiative at the Advanced Science Research Center (ASRC) at the Graduate Center, CUNY. “We were amazed to see that, upon oxidation of these peptide structures, polymeric pigments with a range of colors—from light beige to deep brown- were formed.”

Subsequent, in-depth characterization of the approach demonstrated that further properties, such as UV absorbance and nanoscale morphology of the melanin-like materials, could also be systematically controlled by the amino acid sequence of the tripeptide. 

“We found that the key to achieving polymers with controlled disorder is to start from systems that have variable order built in,” said Ayala Lampel, a postdoctoral ASRC researcher and the paper’s first author. “First, we figured out how the amino acid sequence of a set of tripeptides gives rise to differently ordered architectures. Next, we leveraged these ordered structures as templates for catalytic oxidation to form peptide pigments with a range of properties.” 

The findings published in Science build on previous research conducted by Ulijn, who is also the Albert Einstein Professor of Chemistry at Hunter College and a member of the biochemistry and chemistry doctoral faculty at the Graduate Center. His lab will now turn its attention to further clarifying the chemical structures that form and expanding the resulting functionalities and properties of the various melanin-like materials they produce. The researchers are also pursuing commercialization of this new technology, which includes near-term possibilities in cosmetics and biomedicine.

Christopher J. Bettinger, a Carnegie Mellon University researcher who specializes in melanin applications in energy storage, collaborated with the ASRC team on the current work. Among the materials discovered, he found that two-dimensional, sheet-like polymers show significant charge-storage capacity. “Expanding the compositional parameters of these peptides could substantially increase the utility of the resulting pigments, and this research can also help us better understand the structural property and functions of natural melanins,” Bettinger said.

In addition to Ulijn, Lampel and Bettinger, the research team also included Scott A. McPhee, Tai-De Li and Rinat R. Abzalimov of the ASRC; Sunita Humagain, Hunter College and the Graduate Center; Steven G. Greenbaum and Barney Yoo, Hunter College; Hang-Ah Park, Carnegie Mellon University; Tell Tuttle and Gary G. Scott, University of Strathclyde; Doeke R. Hekstra, Harvard University; Pim W.J.M. Frederix, University of Groningen, The Netherlands; and Chunhua Hu, New York University. 

Funding for the research was provided in part by the U.S. Air Force. Additional funding was provided by the Israeli Council of Higher Education (Postdoctoral Fellowship).

Top Photonics Researcher Andrea Alù Named a Director of the Advanced Science Research Center at the Graduate Center of the City University of New York

Andrea Alù, renowned engineer and photonics researcher, has been named the founding director of the Photonics Initiative at the Advanced Science Research Center (ASRC) at the Graduate Center of the City University of New York.

Alù, who will also hold the title of Einstein Professor of Physics at the Graduate Center in affiliation with the Department of Electrical Engineering at The City College of New York, comes to the ASRC from the University of Texas at Austin where he was the Temple Foundation Endowed Professor #3 in the Cockrell School of Engineering. He was also a member of the Cockrell School’s Wireless Networking and Communications Group and the head of the Metamaterials and Plasmonic Research Laboratory.

The ASRC appointment marks the latest achievement in an impressive career.

He is a recent recipient of the Alan T. Waterman Award (2015) from the National Science Foundation — one of the top prizes for scientists and engineers in the United States. Winners are selected based on the innovation of their research and their overall impact on their field and receive $1 million in research funding.

Alù is best known for his breakthroughs in invisibility cloaking, or making objects transparent to incoming microwave signals. He realized the first freestanding three-dimensional invisibility cloak. He also developed the first nonreciprocal acoustic circulator — or one-way sound device.

His discoveries in metamaterials and plasmonics have broad implications for a range of sectors, including defense, communications, medical imaging, acoustics, mechanics, and robotics.

“I am very excited to be selected as the director of the Photonics Initiative at the ASRC, and I look forward to the opportunity to establish a recognized center of excellence in photonics and electromagnetics in New York City,” Alù said. “The resources and research culture located at the ASRC will be a boon to my research, and I am intrigued by the collaborations between my lab and the other initiatives at the center.”

“Andrea is an innovative thinker, dedicated researcher, and excellent teacher whose work has the potential to transform not just technology but daily life,” said Joy Connolly, provost and senior vice president of the Graduate Center. “We are thrilled that he is joining our team of equally accomplished and committed ASRC directors. I am confident that Andrea, in collaboration with his ASRC and Graduate Center colleagues, will put CUNY at the forefront of science research and teaching.”

Alù is the fifth internationally recognized scientist to be named a founding initiative director at the ASRC. He joins Patrizia Casaccia (neuroscience), Kevin H. Gardner (structural biology), Rein V. Ulijn (nanoscience), and Charles J. Vörösmarty (environmental sciences).

“With Andrea’s appointment, we have filled the ASRC’s five directorships, and we couldn’t have found a more qualified candidate,” said Eric Shipp, deputy executive director of the ASRC. “The ASRC is designed to be a hub of interdisciplinary research in some of today’s most exciting and important fields. Already, we have supported and produced groundbreaking research, and, with Andrea as our photonics director, that will only accelerate.”

In addition to the Waterman Award, Alù has received the International Commission of Optics Prize in Optics (2016), the Optical Society’s Adolph Lomb Medal (2013), the International Union of Radio Science’s Issac Koga Gold Medal (2011), the Kavli Foundation Early Career Lectureship in Material Science (2016), the Edith and Peter O’Donnell Award in Engineering (2015), the Institute of Electrical and Electronics Engineers Microwave Theory and Techniques Society’s Outstanding Young Engineer Award (2014), the International Union of Pure Applied Physics Young Scientist Prize in Optics (2013), the NSF CAREER Award (2010), the Air Force Office of Scientific Research Young Investigator Award (2010), the Defense Threat Reduction Agency Young Investiator Award (2011), the Leopold B. Felsen Award for Excellence in Electrodynamics (2008), and several other awards. He has twice been named a finalist of the Blavatnik National Award for Young Scientists (2016 and 2017).

Alù is a fellow of the Optical Society of America (OSA), the Institute of Electrical and Electronics Engineers (IEEE), the Americal Physical Society (APS), and the International Society for Optics and Photonics (SPIE). He is also a Simons Foundation Investigator in Physics and a distinguished lecturer for the IEEE Antennas and Propagation Society and the OSA.

He holds more than a dozen patents and patent applications and has co-authored more than 500 frequently cited contributions to scientific literature. He serves on the editorial boards of several international journals including Physical Review B, New Journal of Physics, and Advanced Optical Materials.

Alù has a Ph.D., M.S., and an undergraduate degree from the University of Roma Tre in Rome, and he conducted his postdoctoral research at the University of Pennsylvania.

He begins his appointment at the Graduate Center in early 2018.

Groffman’s Study into Urban Ecosystem Homogenization published in Nature Ecology & Evolution

Expansion of urban, suburban and exurban land in the United States over the past several decades has led to neighborhoods in very different parts of the country featuring patterns of roads, residential lots, commercial areas and aquatic features that are more similar to each other than the native ecosystems they replaced.

In research funded by the National Science Foundation (NSF)’s Macrosystems Biology program, a team led by a City University of New York (CUNY) scientist has explored the effects of such urban homogenization on plant biodiversity, soil and nutrient processing, microclimate and hydrography at the continental scale. Results from this work, conducted in residential areas of six cities across the United States, recently appeared in an issue of Nature Ecology & Evolution.

“While urban land use occupies a relatively small area of the Earth’s surface, suburban and exurban land use cover much larger areas,” said lead researcher Peter Groffman, Professor with the Environmental Sciences Initiative at the Advanced Science Research Center (ASRC) at the Graduate Center, CUNY. “Moreover, urbanization has impacts on processes such as plant community assembly and ecosystem function far beyond residential parcels and landscapes that are evident at regional and continental scales.”

Landscape cultivation closely associated with residential planning has led to the homogenization of certain soil processes, as well as plant community composition. Soil parameters — ranging from moisture content to microbial biomass — varied less between residential sites in Boston, Baltimore, Miami, Minneapolis, Phoenix and Los Angeles than among their nearby, natural reference sites. Only carbon sequestration differed among the sites, likely due to the effects of differing climate.

Because residential areas have similar landscaping, flora in urban, suburban and exurban areas have lower turnover in species, resulting in higher species richness — due to the high number of exotic species — but lower diversity than flora in natural areas. These cultivated species may adapt to become part of the natural flora, but such assemblages have serious implications for local bird and insect communities, since these animals have strong associations with local, native plants.

By focusing on human actions at multiple spatial and temporal scales — parcel, neighborhood and regional, among others — researchers showed the diversity, composition and structure of the residential macrosystem will see dramatic changes in the next 50 to 100 years at a potentially continental scale, as a result of its ever-growing expansion into both agricultural and undeveloped areas.

The observations captured in this paper serve as a basis for new research just now underway and led by Groffman, also Professor of Earth and Environmental Sciences at Brooklyn College. This work, which also was funded by NSF’s Macrosystems Biology program, will address the factors that contribute to stability and change in what is termed the ‘American residential macrosystem’. It will determine how and if changing desires and needs to water use efficiency, wildlife and runoff control will lead to significant changes in the structure and function of these ecosystems across the U.S. at different spatial scales (parcel, landscape, region, continent). A key part of this new work is the design and testing of different scenarios for what the future American residential macrosystem may look like, and their ecological implications.

Click here to read the full paper.