Researchers at Kansas State University have developed a new mechanical adhesive whose unique properties might make it well suited to be in every astronaut's toolbox. Unlike traditional chemical adhesives which can become brittle when moisture is removed, this new adhesive - made from peptides - actually forms a stronger bond. This makes it ideal for use in low-moisture environments such as space, where astronauts might use it to reattached tiles to a space shuttle. The unique design even earned the researchers a patent - "pH dependent adhesive peptides".

"The adhesive we ended up developing was one that formed nanoscale fibrils that become entangled, sort of like Velcro. It has all these little hooks that come together," said co-creator John Tomich, professor of biochemistry at K-State. "It's a mechanical type of adhesion, though, not a chemical type like most commercial adhesives."

The project began nearly ten years earlier when Xiuzhi "Susan" Sun, professor of grain science and industry, and Xinchun Shen, a postdoctal researcher in her lab, were studying the adhesive properties of soybean proteins. Needing an instrument to synthesize protein peptides, Sun contacted Tomich.

As luck would have it, Tomich's lab had previously discovered a peptide that had cement-like properties. Tomich said he knew it was unusual but had set it aside to pursue other interests.

"When Dr. Sun and I resurrected this protein, we didn't use the whole thing -- just a segment of it," Tomich said. "We isolated a certain segment where the cells are highly attracted to each other and form these fibrils."

Since their collaboration Tomich has taken the same sequence and changed the way it was designed. The new peptide, he said, will have an eye toward gene therapy.

Sun's lab is trying to optimize the sequence against adhesion, as well as study how peptide sequences influence adhesion properties and surface energy.

"I continue studying protein structures and functional properties in terms of adhesion -- folding, aggregation, surface energy and gelling properties -- so we can rationally design and develop biobased adhesives using plant proteins," she said.

Additional information on the application possibilities and advantages of peptide adhesives.

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