by Thea Singer
Electronic screens whose color-changing technology is inspired by squids. Skin constructed in the lab from protein fibers to mimic the aging process and test products that may slow it down.
Those are just two of the research projects underway in the lab of Leila Deravi, who joined the Northeastern faculty this fall as assistant professor in the Department of Chemistry and Chemical Biology.
In Deravi’s interdisciplinary approach, researchers in chemistry, materials science, mechanical engineering, and physics work together to investigate the proteins that drive complex biological systems and then build materials in the lab that replicate those systems. Practical applications down the road include textiles and electronic screens that change color by incorporating a squid’s ability to slip from, say, white yellow to brown to merge with the environment. Another is a face cream infused with a chemical that Deravi’s team is working on to strengthen skin proteins, reducing wrinkles.
“I’ve always been really interested in replicating natural systems but using advanced technologies to do so,” says Deravi, who was assistant professor of chemistry and materials science at the University of New Hampshire before coming to Northeastern. Those advanced technologies include formulating inks containing the proteins Deravi is studying and using inkjet technology to print out the materials synthesized from them for evaluation.
Deravi praises the Barnett Institute of Chemical and Biological Analysis at Northeastern, where she is a faculty fellow, as a place where her multiple research interests not only come together but also have the opportunity to grow. “The institute gives me the ability to tap into fantastic resources and expertise,” she says.
Inspired by nature
Marine mollusks such as the octopus or squid have the uncanny ability to undergo rapid, adaptive camouflage, changing the color of their skin within hundreds of milliseconds. Deravi and her colleagues study organs called chromatophores that lie just beneath the skin of these animals and contain a sac full of pigment that may be black, brown, orange, red, or yellow. The animals’ skin color changes as the distribution of the pigments shifts to reflect, absorb, or transmit light.
“We have developed a specific extraction protocol that enables us to isolate these pigments,” says Deravi. “Our goal now is to understand how they and other protein-based structures in the chromatophore contribute to the adaptive color in cephalopods such as squids.”
Her experiments address various mind-opening questions: What happens to the squid’s pigment color when an electric charge is applied to it or light is shone on it? How can her team maintain control of changes in color that they bring about? When the pigments, which Deravi’s team extracts from the animals but also makes in the lab, are integrated into natural or synthetic fabrics, will the production of color-changing textiles be possible?
The researchers have performed calculations showing that the pigments also behave like organic semiconductors—they are able to conduct small amounts of electricity. “Does this mean that a squid or octopus is essentially an underwater electronic display?” Deravi asks.
In September, she received a grant from the U.S. Army Research Office to answer those and other questions.
The skin research is less far along. “Our first goal is to identify the key proteins involved in the aging process,” says Deravi. Collagen, elastin, and fibronectin are among them. Next the researchers will construct fibers out of the human-derived proteins they get from a chemical company and weave them into a network—in other words, they will construct synthetic skin. Using custom-built machines in the lab, they will then test the mechanical properties of the fibers over time to explore how aging affects them.
“My appointment is in chemistry, but I work at the interface of chemistry, biology, engineering, and materials science,” says Deravi. She notes that she finds the recent establishment of the Department of Bioengineering program at Northeastern particularly exciting. “The university’s continuing commitment to expanding interdisciplinary research makes this a great time for new scientists like me to be on campus.”