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Scientists find better way to make use of lobster shells



ELLSWORTH — Last year, Maine saw more than 110 million pounds of lobster landed at docks along the coast from Kittery to Cobscook Bay. Those landings put more than $450 million in the pockets of Maine lobstermen and, after those lobsters were consumed, left some 33,000 tons of lobster shells behind to be disposed of.

Recently, a group of researchers at McGill University in Montreal announced that they may have found an easy way to turn those mountains of empty lobster shells, not to mention shells from crabs, shrimp and even insects, into a biodegradable plastic. That plastic could be used for surgical implants, drug delivery systems or even as a package wrap. But not tomorrow.

“It’s a little far from commercial applications,” Audrey Moores, an associate professor of applied chemistry at McGill, said earlier this month. She leads the Moores Research Group at the university, which recently announced the results of nearly three years of research.

The process, which calls for grinding hard shells made of chitin into a fine powder, then treating that powder with sodium hydroxide and heat, produces chitosan, a material already used in biomedical applications but difficult to produce in substantial quantities.

According to Moores, the process that she and graduate student Thomas DiNardo have developed has the potential for the large-scale production of chitosan for such medical uses as biodegradable surgical sutures that can decompose in the patient’s body rather than having to be removed. Eventually, she said, material produced using the new method could be used for 3-D printing of items such as surgical implants that are “individually designed” for each patient. When will those printed devices become available?

“That’s hard to answer,” Moores said. “It could be three to five years.”

Moores said the process developed by her laboratory to produce chitosan on a large scale has potential for improving products outside the biomedical field.

“We’re also looking into mixing it with other plastics to make a moldable material,” Moores said.

One source of chitin that seems almost inexhaustible is the exoskeleton — the hard outer shell — that protects all insects, as well as arthropods such as spiders and other animals including crustaceans.

Moores has worked with some insects in her laboratory. Recently she made a connection with a company that makes protein power from insects and has to dispose of their shells.

The chitosan project is just part of Moores’ work on polymers, molecules with a long necklace-like chain of repeated subunits. Man-made polymers are the basis for all kinds of plastics in common usage, Chitin is a natural polymer and, Moores said, “we have preserved the polymer chain to make a new polymer.”

Moores has been engaged in research involving “green chemistry” for at least a decade. She credits DiNardo, her graduate student who, she said, raised the idea of finding a better method for the deacetylation of chitin — the technical description of the process that creates chitosan from chitin.

“I’ve been interested in bio-materials for awhile,” Moors said. “Chitin is a fascinating material. It was almost natural that we should look into it.”

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