Gizmorama - January 16, 2017

Good Morning,

Here's a wonderful headline: The world's tightest knot could yield new building materials. Science never lets you down. You have to read this article.

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin

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*-- Scientists train DNA nanotubes to self-assemble a bridge between molecules --*
BALTIMORE - Researchers at Johns Hopkins University have trained DNA nanotubes to construct a bridge across a a cell culture dish.

"If this process were to happen at the human scale, it would be like one person casting a fishing line from one side of a football field and trying to hook a person standing on the other side," Abdul Mohammed, a postdoctoral fellow at JHU, explained in a news release.

Mohammed works in the lab of Rebecca Schulman, an assistant professor of chemical and biomolecular engineering and senior of author a new paper describing the microscopic feat, published this week in the journal Nature Nanotechnology.

DNA nanotubes are microscopic building blocks composed of synthetic nucleic acid structures. Their structural integrity is valued in the nanotechnology construction field.

Because synthetic nucleic acid structures can self-assemble into chains, forming long nanotubes, they were an obvious choice for microscopic bridge building. In the lab, Schulman and her fellow researchers attached DNA nanotubes to two molecular end posts in a Petri dish.

The DNA structures self-assemble a chain as they wriggle toward the center of the dish, exploring new territory. Eventually, they bump into each other and forge a solid connection, forming a bridge.

Researchers used fluorescent dyes and a microscope to film the bridge-building action. Depending on how far apart the molecular anchors are, the bridge can take anywhere from several hours to a few days to complete.

Scientists believe the technology can be used to build connections between biomedical devices and the surfaces of cells.




* The world's tightest knot could yield new building materials *
MANCHESTER, England - Scientists from the University of Manchester have tied the world's tightest knot using molecular strands.

The knot was made possible by a new technique for braiding molecular strands. The technique has enabled scientists to loop strands into tighter and more complex formations. Ultra-tight molecular knots could pave the way for a new class of advanced materials.

The record-setting knot is a 192-atom closed loop with eight crossings; it measures 20 nanometers in length.

With their breakthrough molecular tying process, scientists will be able to test how different knot formations affect strength and other physical properties. Scientists expect their work -- detailed in the journal Science -- to have a ripple effect in the field of materials science.

"Tying knots is a similar process to weaving so the techniques being developed to tie knots in molecules should also be applicable to the weaving of molecular strands," David Leigh, a chemistry professor at the University of Manchester, said in a news release. "For example, bullet-proof vests and body armour are made of kevlar, a plastic that consists of rigid molecular rods aligned in a parallel structure -- however, interweaving polymer strands have the potential to create much tougher, lighter and more flexible materials in the same way that weaving threads does in our everyday world."

The process of knot creation is called "self assembly." Molecular strands are woven around metal ions, with woven cross points precisely positioned. A chemical catalysts fuses the ends of the strands, forming a closed loop.

"The eight-crossings molecular knot is the most complex regular woven molecule yet made by scientists," Leigh said.

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