Nano-particles Release Insulin into Diabetics’ Bloodstream

QDOTS imagesCAKXSY1K 8Diabetics could cut their need for injections to less than once a week thanks  to new insulin-releasing “smart” particles.

Researchers in the US have developed a type of nanoparticle that  automatically releases insulin into the blood when glucose levels get too high,  and have demonstrated that its effects last for 10 days in mice.

Regular injections of the particles could mean type 1 diabetics  wouldn’t have to check their blood sugar levels several times a day, or inject  the exact right amount of insulin when needed, which can result in too high or  low doses being administered, with further health problems following.

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‘We’ve created a ‘smart’ system that is injected into the body and  responds to changes in blood sugar by releasing insulin, effectively controlling  blood-sugar levels,’ said Dr Zhen Gu, an assistant professor in the joint  biomedical engineering program at North Carolina State University and the  University of North Carolina.

‘This technology effectively creates a ‘closed-loop’ system that mimics  the activity of the pancreas in a healthy person, releasing insulin in response  to glucose level changes. This has the potential to improve the health and  quality of life of diabetes patients.’

The nanoparticles have a solid core of insulin surrounded by a layer of  a modified glucose-based material known as dextran and another of glucose  oxidase enzymes.

When the enzymes are exposed to high glucose levels they effectively  convert the sugar into gluconic acid, which breaks down the modified dextran and  releases the insulin.

The insulin then brings the glucose levels under control. The gluconic  acid and dextran are biocompatible and dissolve in the body.

The nanoparticle cores are given a biocompatible coating that makes  them positively or negatively charged, causing them to form a network that  prevents them from dispersing throughout the body.

The positively charged coatings are made of chitosan (a material  normally found in shrimp shells), abnd the negatively charged coatings are made  of alginate (a material normally found in seaweed).

When the solution of coated nanoparticles is mixed together, the  positively and negatively charged coatings are attracted to each other to form a “nano-network.”

Once injected into the subcutaneous layer of the skin, the nano-network  holds the nanoparticles together. Both the nano-network and the coatings are  porous, allowing blood – and blood sugar – to reach the nanoparticle cores.

Gu’s research team is now in discussions to move the technology into  clinical trials for use in humans.

A paper on the research has been published in the scientific journal  ACS Nano.

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Nanotechnology triples solar efficiency

By | December 11, 2012, 7:49 PM PST

Nanotechnology traps light for significantly greater solar efficiency.

Nanotechnology traps light for significantly greater solar efficiency.

Princeton University recently announced a new nanotechnology that has demonstrated the ability to triple the efficiency of solar cells by eliminating two of the primary reasons why light is reflected or lost. This breakthrough was achieved by applying a “nano-mesh” to plastics, which would make way for inexpensive, flexible devices, or even greatly improve the efficiency of standard photovoltaic panels, the researchers say.

The nano-mesh is designed to dampen reflection and trap light to be converted into electrical energy (existing technologies cannot fully capture light that enters the cell). Only 4 percent of light is reflected, and as much as 96 percent is absorbed, a press release noted. Its overall efficiency in converting light to energy is 52 percent higher than conventional cells in direct sunlight and up to 175 percent greater on cloudy days with less sun.

For reference, North Carolina’s Semprius Inc., a Siemens backed venture, revealed a prototype of what it called the world’s best solar efficiency at 33.9 percent earlier this year. Princeton didn’t reveal its overal efficiency.

Princeton’s findings were first reported in the November 2nd edition of the journal Optics Express, and exceeded the scientists’ expectations, according to project lead Dr. Stephen Chou. The research was funded by the Defense Advanced Research Projects Agency, the Office of Naval Research and the National Science Foundation. Chou said that the technology would become even more efficient with more experimentation.

Outside of the lab, U.S. PV maker ecoSolargy has already used nanotechnology to boost solar efficiency by an estimated 35 percent over a 20-year period by filling tiny holes that can accumulate dirt, dust, or water. Other approaches that are being taken to improve solar efficiency have been inspired by nature.

A team of researchers at the University of Wisconsin-Madison recently created a design that emulates how sunflowers move to maximize light exposure through an adaptation called heliotropism. One could imagine that any combination of these technologies would constitute another leap forward for solar power.

(Illustration by Dimitri Karetnikov/Chou Lab)QDOTS imagesCAKXSY1K 8