Man-made retina' to help blind see

WASHINGTON: Scientists claim to have developed an 'artificial retina' which could restore near-normal vision to the blind, a finding which can benefit millions.
Researchers made the blind mice see clearly with radical new implant and the creatures' vision could track images and discern features.
This new approach provides hope for the 25 million people worldwide who suffer from blindness due to diseases of the retina.
The researchers say they have also cracked the code for a monkey retina, which is essentially identical to that of a human and hope to quickly design and test a device that blind humans can use. As drug therapies help only a small fraction of this population, prosthetic devices are their best option for future sight.
"This is the first prosthetic that has the potential to provide normal or near-normal vision because it incorporates the code," Dr Sheila Nirenberg , neuroscientist from Weill Cornell Medical College in New York ,said.
"We can make blind mouse retinas see and we're moving as fast as we can to do the same in humans," Nirenberg, who is honing the technique, said in a statement.
The technique, using hightech spectacles containing a tiny camera rather than surgery , could be tested on people for the first time in just one to two years.
"It's an exciting time. We can make blind mouse retinas see, and we're moving as fast as we can to do the same in humans ," said Nirenberg in a statement. "This has all been thrilling , I can't wait to get started on bringing this approach to patients," she said.
The first beneficiaries are likely to be sufferers of age-related macular degeneration, the most common cause of blindness in the elderly.
There are few treatments and no cure for the condition which makes it difficult or impossible to carry out everyday tasks such as reading, driving and watching television. Scientists have already created implantable chips that restore some vision.
But Nirenberg says that her technique produces a much clearer picture. In fact, vision is close to normal.
No comments:

Biotechnology

Making Human Organs on a Chip

By  on June 27, 2012
 
Disembodied human organs floating in jars are a staple of any cinematically correct mad-scientist laboratory. Researchers at Harvard’s Wyss Institute have done one better. They’ve created an organ on a chip: a device the size of a thumb drive (or, for that matter, a thumb), containing living cells, that mimics the behavior of a human organ.
The researchers have created a lung on a chip, as well as an intestine, a kidney, and bone marrow. A heart is in the works. Devices like these could radically streamline the drug testing process—currently expensive, inefficient, and lethal for many animals—and shed light on how diseases develop.
The organs on chips that the Wyss researchers have produced look a lot more like chips than organs. They’re transparent plastic rectangles with tiny channels running through them, connected to tubes and wires. “It’s the minimal physically functional section of an organ,” says Dr. Donald Ingber, who runs the institute and works with the researchers creating the various devices.
The lung on a chip has a channel running down its center with a porous membrane bisecting it lengthwise. On one side of the membrane is a layer of human capillary cells, with a blood-like fluid running along them; on the other side a layer of human air sac cells, with air running along them. Just as in a lung, the interaction of the two types of cells pulls oxygen from the air and fixes it in blood. The flexible plastic of the chip expands and contracts as the lung “breathes.”
The creation of the chips was enabled by advances in the semiconductor industry that allowed for precision manufacturing at cellular scales. But they also grew out of the increasing appreciation among biologists of the role that mechanical factors play in how the body develops and works. Ingber himself did much of the research that illustrated the point, showing, for example, that simply squeezing certain cells in a developing mouse embryo leads them to begin to differentiate into organs.
The gut on a chip that the Wyss researchers developed illustrates the point in its own way. The tiny artificial organ mimics peristalsis, the rippling contractions of the human digestive system. In so doing it surprised its creators by causing the intestinal cells lining the chip to spontaneously form the distinctive villi structure they assume in actual human intestinal walls.
The organs on chips can’t actually do all the things real organs do. Among other things, they don’t have nerve cells, and you wouldn’t want to try to digest a hot dog with the gut on a chip. But in other ways they seem to replicate the performance of actual organs very well. When the finicky microbes that live in an actual human intestine—and perform vital functions there—are introduced into the gut on a chip, they find the environment quite congenial. And the researchers who designed the lung on a chip discovered they were able to use it to predict how the lungs in living, breathing animals absorbed the particulate matter in air pollution.
The Wyss Institute is already working with a few pharmaceutical companies to design drug tests that use the organs on chips. Animal tests, after all, are expensive, increasingly controversial, and often don’t predict how humans will react to a compound. According to Ingber, the chips will also allow researchers to observe the mechanism of both diseases and drugs.
“Sometimes you might think your drug works this way. You give it for a month, kill the animal, then do a histological study,” Ingber says. That means you have to infer the mechanism after the fact. The chips, on the other hand, would allow researchers to watch the process in real time. Once they’re perfected, they can be cheaply made, and tests run repeatedly at little cost.
And once enough organs on chips have been developed, Ingber envisions creating an entire human body on chips. A pharmaceutical company could test a drug on the whole body, or on a particular subset of organs, by just plugging them together like strings of Christmas lights.
Bennett is a staff writer for Bloomberg Businessweek.
No comments:

Best-ever quality printing inspired by stained glass

11:27 14 August 2012
Jacob Aron, reporter
1st-Lenafigurepanels.jpg A nanoscale image (a) before the addition of metal and (b) after adding metal layers to the nanostructures in specific patterns (Images: Agency for Science, Technology and Research)
A new way of printing colours at the highest resolution permitted by the laws of physics could be used to create secure watermarks or high-density data storage - not to mention some great-looking pictures.
Joel Yang and colleagues at the Agency for Science, Technology and Research (A*STAR) in Singapore, who created the new technique, were inspired by the colours in stained-glass windows. These are normally made by adding metallic fragments to glass, with light scattering off nanoparticles in the metal to produce a range of colour.
2nd-eye.jpg Zooming in, the specular reflection at the corner of the eye shows the refined colour detail that the new method is able to achieve. The region indicated (right) is made up of nanostructures as observed in the electron micrograph
Each "pixel" in the image is actually made up of four nanoscale cylinders coated in silver and gold. The colour they produce depends on both the diameter and spacing of the cylinders, allowing Yang to "print" a full-colour image just by carving out cylinders at the right scale.
The team tried out their method by printing a 50x50 micrometre copy of "Lena", a photograph of a woman commonly used in image processing tests. This image has a resolution of around 100,000 dots per inches (dpi), compared to the 10,000 dpi images produced by regular printing methods such as inkjet and laser printers.
Yang and colleagues choose this figure because it corresponds to a fundamental optical limit. Visible light, with an average wavelength of 500 nanometres, can only distinguish between objects that are half that distance apart - any closer than 250 nanometres, and the two would blur into one.
If the new method can be scaled up to print at regular sizes the resulting images will be of incredibly high quality. Alternatively, Yang and colleagues could apply their printing technique to creating tiny watermarks for security. The method of printing nanostructures very close together could also be used to create high-density versions of optical storage discs such as DVDs.
No comments:
Subscribe to: Comments (Atom)