Fuente: Futurity
Expuesto el: martes, 10 de septiembre de 2013 15:57
Autor: A'ndrea Elyse Messer-Penn State
Asunto: New synthetics from squids' sucker teeth?
Penn State rightOriginal Study Posted by A'ndrea Elyse Messer-Penn State on September 10, 2013 Researchers have combined several approaches to test natural materials from squid, mussels, and marine snails that may lead to a wide range of biologically inspired products. The researchers combined three approaches—protein studies, materials science, and RNA sequencing—that would allow them to quickly characterize the materials and translate their molecular designs into useable, unique materials. "Biological methods of synthesizing materials are not new," says Melik C. Demirel, professor of engineering science and mechanics at Penn State. "What is new is the application of these principles to produce unique materials." Demirel and colleagues looked at proteins because they are the building blocks of biological materials and also often control sequencing, growth, and self-assembly. RNA produced from the DNA in the cells is the template for biological proteins. Materials science practices allow researchers to characterize all aspects of how a material functions. "One problem with finding suitable biomimetic materials is that most of the genomes of model organisms have not yet been sequenced," says Demirel. "Also, the proteins that characterize these materials are notoriously difficult to solubilize and characterize." The researchers examined three model systems: egg case membranes of a tropical marine snail, a mussel foot, and jumbo squid sucker ring teeth. Snail, mussel, squidThe egg case membranes of a tropical marine snail are intriguing because they have unusual shock-absorbing qualities and elasticity. The analysis shows that the material has a coiled structure with cross-linking that absorbs energy. Analysis of a mussel foot showed that a species-to-species variation exists in mussels, including unusual variation in the protein. These variations suggest that protein engineering could produce a range of self-healing properties.
The final model used jumbo squid sucker ring teeth (SRT), grappling-hook-like structures used for predatory attacks. Analysis of the squid teeth showed nanotubular structure and strong polymers. While there was some similarity to silk and oyster shell matrix proteins, the protein was novel and the researchers named it Suckerin-39. Further analysis showed that Suckerin-39′s structure allowed it to be reprocessed into a variety of shapes. "While some biological materials have interesting properties, they cannot be reshaped or remolded because they do not soften upon heating," says Demirel. "The SRT is an elastomer, which is moldable, it is a thermoplastic and can be reshaped." The materials properties of SRT do not change after heating and reshaping. "We now know that nature can do all kinds of things including nanotubes, cross-linked structures, and shock-absorbing coils," says Demirel. "Now that we know the secrets, we need to find ways to mimic the structures and do it inexpensively." This may mean having bacteria produce the required proteins or some other biomimetic approach. "Integrating these ecofriendly materials into devices for wetting, friction, and transport is relatively straightforward and will constitute an important part of our future research," says Demirel. Ali Miserez, an assistant professor at Nanyang Technological University in Singapore, led the project, which was funded in part by the Office of Naval Research and the National Institutes of Heath. The results of the work appear in a recent issue of Nature Biotechnology. Source: Penn State
|
