Drunk Mice Sober Up Fast After Nanoparticle Injection

enzymes
Enzymes: Three enzymes are combined with a DNA scaffold along with their enzymatic inhibitors, leading to a triple-compound architecture. A thin polymer is grown around the enzymes, encapsulating them in a sort of nano-pill. Enzymes working in close proximity ensures they can clean up after each other’s toxic byproducts.

Multiple enzymes delivered in a nanocapsule could work as an alcohol antidote, reducing blood alcohol levels and preventing liver damage.

A new nanostructured enzyme complex can lower blood alcohol levels in intoxicated mice, according to a new study. The nano-pill, which assembles and encapsulates three types of enzymes, could work as a type of alcohol antidote. It also suggests that this unique protein-tailoring method could be used for lots of ailments.

Enzymes are proteins that spark a whole host of biological processes, but many can only work when they are in specific places in a cell, or when they are accompanied by other enzymes. Proper positioning speeds up chemical reactions, and it mitigates the potentially nasty byproducts of some of those reactions. Researchers have been trying to use enzymes as drugs for a long time, but it has been difficult to produce the right combinations, meaning they might not function properly or they might be rejected by the body.

After you drink alcohol, it loiters in your bloodstream until enzymes produced in the liver can break it down. But this takes the liver some time, and meanwhile, you’re intoxicated. This new enzyme injection does the same job much quicker, helping the liver break down alcohol and thus sobering up a tipsy mouse in a hurry. This also helps protect the hard-working liver from damage.

Researchers in California packed up complementary enzymes in a nano-capsule, producing what basically amounts to a tiny enzyme pill. The capsule coating, made of a superthin polymer, keeps the enzymes together and protects them from breaking down in the body.

Led by Yunfeng Lu, a chemical and biomolecular engineering professor at UCLA, researchers injected mice with three enzymes related to the breakdown of sugars, and after this worked, they tried it with two enzymes related to the breakdown of alcohol, alcohol oxidase (AOx) and catalase. They wanted to test the enzymes as both an intoxication preventive and a treatment.

When mice were fed a diet of alcohol and the nano-capsule at the same time, their blood alcohol concentrations were greatly reduced within 30-minute increments, compared to mice that were fed just alcohol or alcohol plus one of the enzymes. The team also tested it on drunk mice, and found the treatment greatly lowered yet another enzyme, alanine transaminase, which is a biomarker for liver damage.

“Nanocomplexes containing alcohol oxidase and catalase could reduce blood alcohol levels in intoxicated mice, offering an alternative antidote and [preventive treatment] for alcohol intoxication,” the authors write. The paper appears in Nature Nanotechnology.

http://www.popsci.com/science/article/2013-02/drunk-mice-sober-after-nanoparticle-injection

Scientists at Cornell create Terminator-like organic metamaterial that flows like liquid and remembers its shape

 

 

DNAletters

 

birdsnests

A bit reminiscent of the Terminator T-1000, a new material created by Cornell researchers is so soft that it can flow like a liquid and then, strangely, return to its original shape.

Rather than liquid metal, it is a hydrogel, a mesh of organic molecules with many small empty spaces that can absorb water like a sponge. It qualifies as a “metamaterial” with properties not found in nature and may be the first organic metamaterial with mechanical meta-properties.

Hydrogels have already been considered for use in drug delivery — the spaces can be filled with drugs that release slowly as the gel biodegrades — and as frameworks for tissue rebuilding. The ability to form a gel into a desired shape further expands the possibilities. For example, a drug-infused gel could be formed to exactly fit the space inside a wound.

Dan Luo, professor of biological and environmental engineering, and colleagues describe their creation in the Dec. 2 issue of the journal Nature Nanotechnology.

The new hydrogel is made of synthetic DNA. In addition to being the stuff genes are made of, DNA can serve as a building block for self-assembling materials. Single strands of DNA will lock onto other single stands that have complementary coding, like tiny organic Legos. By synthesizing DNA with carefully arranged complementary sections Luo’s research team previously created short stands that link into shapes such as crosses or Y’s, which in turn join at the ends to form meshlike structures to form the first successful all-DNA hydrogel. Trying a new approach, they mixed synthetic DNA with enzymes that cause DNA to self-replicate and to extend itself into long chains, to make a hydrogel without DNA linkages.

“During this process they entangle, and the entanglement produces a 3-D network,” Luo explained. But the result was not what they expected: The hydrogel they made flows like a liquid, but when placed in water returns to the shape of the container in which it was formed.

“This was not by design,” Luo said.

Examination under an electron microscope shows that the material is made up of a mass of tiny spherical “bird’s nests” of tangled DNA, about 1 micron (millionth of a meter) in diameter, further entangled to one another by longer DNA chains. It behaves something like a mass of rubber bands glued together: It has an inherent shape, but can be stretched and deformed.

Exactly how this works is “still being investigated,” the researchers said, but they theorize that the elastic forces holding the shape are so weak that a combination of surface tension and gravity overcomes them; the gel just sags into a loose blob. But when it is immersed in water, surface tension is nearly zero — there’s water inside and out — and buoyancy cancels gravity.

To demonstrate the effect, the researchers created hydrogels in molds shaped like the letters D, N and A. Poured out of the molds, the gels became amorphous liquids, but in water they morphed back into the letters. As a possible application, the team created a water-actuated switch. They made a short cylindrical gel infused with metal particles placed in an insulated tube between two electrical contacts. In liquid form the gel reaches both ends of the tube and forms a circuit. When water is added, the gel reverts to its shorter form that will not reach both ends. (The experiment is done with distilled water that does not conduct electricity.)

The DNA used in this work has a random sequence, and only occasional cross-linking was observed, Luo said. By designing the DNA to link in particular ways he hopes to be able to tune the properties of the new hydrogel.

The research has been partially supported by the U.S. Department of Agriculture and the Department of Defense.

http://www.news.cornell.edu/stories/Dec12/ShapeGel.html

Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.