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Artificial cornea is both strong and clear
Technology
A 3D software model of London containing over 3 million buildings in photorealistic detail is now unlikely to reach the public because of a dispute between a UK government agency and Google. Built by the Centre for Advanced Spatial Awareness (CASA) at University College London and integrated with free mapping software Google Earth, the model would have helped the public become involved in city planning, by showing how buildings fit in with the landscape before they are built. It would also have demonstrated the potential effects of global warming with a feature that showed rising waters flooding the virtual streets. CASA used MasterMap, owned by Ordnance Survey, Great Britain’s national mapping agency, which details every fixed feature in the country larger than a few metres. This gave the team
Replacement cornea makes clear difference
AN ARTIFICIAL cornea has been created that is as strong and clear as the real thing. It could allow millions of people with damaged corneas to see. Corneal blindness can be caused by disease, injury or infection of the eye’s clear surface. It can be cured 28 | NewScientist | 25 August 2007
JASON HAWKES
Virtual London shelved in row over map data
accurate footprints of all buildings inside the M25 motorway that encircles London. They then added virtual buildings to the map, using heights obtained with laser measurements, and lastly enhanced the model by adding realistic textures. Google had hoped to integrate the model with Google Earth and pay a fixed fee for MasterMap, arguing that the public would only see the visualisation, not the raw data. However, OS wanted to follow its usual terms, under which customers pay based on the
with a transplant from a human donor, but donors are scarce. The World Health Organization estimates that 10 million people worldwide are blind because of defective corneas, yet only 100,000 receive transplants each year. Artificial corneas made from flexible hydrogels – polymers that absorb water – are now available, but they are not permeable enough to support epithelial cells on their surface. These cells guard against bacteria and stop natural corneas becoming cloudy, by preventing proteins from sticking to them. Adding more water to the hydrogels allows glucose to diffuse through them and nourish epithelial cells on the surface, but it also weakens
OS says that the heat-loss map is an exception because it is owned by a non-profit group. CASA’s Andrew Hudson-Smith disagrees: “They are going through a crisis and don’t know how to react to the Web 2.0 world. ” Timothy Foresman, directorgeneral of the fifth International Symposium on Digital Earth in San Francisco in June, fears that OS’s decision could set a precedent: “The OS model is a dinosaur,” he says. “If the UK community doesn’t band together and make this a cause célèbre, then they will find the road is blocked as further uses [of the OS data] become known.” For now, the public will have to wait until Microsoft releases its –Public city, private layout– own model as part of its Virtual Earth software, which won’t rely on OS data. Meanwhile the UKnumber of people using the data. based OpenStreetMap project is Hopes were raised earlier this year when a map of heat loss over encouraging people to make their own measurements and post London, which uses MasterMap, them online, where they might appeared online. However, an OS then be used to create an online statement this month dashed model. “OS will find that all the these hopes: “There are people they’re restricting will go differences in what Google wants and what our licensing framework and get the data for themselves and release it for free,” says the permits that mean we have not project’s founder, Steve Coast. been able to reach agreement.” CASA is also planning a model “People will go and get the of London for Second Life, but Hudson-Smith says it won’t be as map data for themselves accurate as the contentious version. David Robson ● and release it for free”
them. So there is a push to develop a synthetic cornea that is both strong and permeable. “The long-term goal is an off-the-shelf cornea that looks and acts like donor tissue,” says Heather Sheardown of McMaster University in Hamilton, Ontario. Now Curtis Frank and colleagues at Stanford University in California have done just that. They took polyacrylic acid, the water-absorbing polymer found in diapers, and crosslinked it with polyethylene glycol, which also absorbs water. The crosslinks mean that the resulting material is 20 times stronger than either of the starting polymers on their own, and about the same strength as a human cornea. Crucially it also has the same water content as
a real cornea, which greatly increases its ability to transport nutrients to the epithelial cells. After forming the material, which was presented at the American Chemical Society meeting in Boston on 20 August, into a 6-millimetrewide disc, the researchers implanted it in rabbits. They found that glucose from the eye diffused through the material and fed the epithelial cells growing on the surface, which had been modified with collagen to promote cell growth. Sheardown is also developing a cornea made from two intertwined polymers. But it does not transport glucose as readily as Frank’s and she has not yet tested it on animals. Aria Pearson ● www.newscientist.com
A 3D software model of London containing over 3 million buildings in photorealistic detail is now unlikely to reach the public because of a dispute between a UK government agency and Google. Built by the Centre for Advanced Spatial Awareness (CASA) at University College London and integrated with free mapping software Google Earth, the model would have helped the public become involved in city planning, by showing how buildings fit in with the landscape before they are built. It would also have demonstrated the potential effects of global warming with a feature that showed rising waters flooding the virtual streets. CASA used MasterMap, owned by Ordnance Survey, Great Britain’s national mapping agency, which details every fixed feature in the country larger than a few metres. This gave the team
Replacement cornea makes clear difference
AN ARTIFICIAL cornea has been created that is as strong and clear as the real thing. It could allow millions of people with damaged corneas to see. Corneal blindness can be caused by disease, injury or infection of the eye’s clear surface. It can be cured 28 | NewScientist | 25 August 2007
JASON HAWKES
Virtual London shelved in row over map data
accurate footprints of all buildings inside the M25 motorway that encircles London. They then added virtual buildings to the map, using heights obtained with laser measurements, and lastly enhanced the model by adding realistic textures. Google had hoped to integrate the model with Google Earth and pay a fixed fee for MasterMap, arguing that the public would only see the visualisation, not the raw data. However, OS wanted to follow its usual terms, under which customers pay based on the
with a transplant from a human donor, but donors are scarce. The World Health Organization estimates that 10 million people worldwide are blind because of defective corneas, yet only 100,000 receive transplants each year. Artificial corneas made from flexible hydrogels – polymers that absorb water – are now available, but they are not permeable enough to support epithelial cells on their surface. These cells guard against bacteria and stop natural corneas becoming cloudy, by preventing proteins from sticking to them. Adding more water to the hydrogels allows glucose to diffuse through them and nourish epithelial cells on the surface, but it also weakens
OS says that the heat-loss map is an exception because it is owned by a non-profit group. CASA’s Andrew Hudson-Smith disagrees: “They are going through a crisis and don’t know how to react to the Web 2.0 world. ” Timothy Foresman, directorgeneral of the fifth International Symposium on Digital Earth in San Francisco in June, fears that OS’s decision could set a precedent: “The OS model is a dinosaur,” he says. “If the UK community doesn’t band together and make this a cause célèbre, then they will find the road is blocked as further uses [of the OS data] become known.” For now, the public will have to wait until Microsoft releases its –Public city, private layout– own model as part of its Virtual Earth software, which won’t rely on OS data. Meanwhile the UKnumber of people using the data. based OpenStreetMap project is Hopes were raised earlier this year when a map of heat loss over encouraging people to make their own measurements and post London, which uses MasterMap, them online, where they might appeared online. However, an OS then be used to create an online statement this month dashed model. “OS will find that all the these hopes: “There are people they’re restricting will go differences in what Google wants and what our licensing framework and get the data for themselves and release it for free,” says the permits that mean we have not project’s founder, Steve Coast. been able to reach agreement.” CASA is also planning a model “People will go and get the of London for Second Life, but Hudson-Smith says it won’t be as map data for themselves accurate as the contentious version. David Robson ● and release it for free”
them. So there is a push to develop a synthetic cornea that is both strong and permeable. “The long-term goal is an off-the-shelf cornea that looks and acts like donor tissue,” says Heather Sheardown of McMaster University in Hamilton, Ontario. Now Curtis Frank and colleagues at Stanford University in California have done just that. They took polyacrylic acid, the water-absorbing polymer found in diapers, and crosslinked it with polyethylene glycol, which also absorbs water. The crosslinks mean that the resulting material is 20 times stronger than either of the starting polymers on their own, and about the same strength as a human cornea. Crucially it also has the same water content as
a real cornea, which greatly increases its ability to transport nutrients to the epithelial cells. After forming the material, which was presented at the American Chemical Society meeting in Boston on 20 August, into a 6-millimetrewide disc, the researchers implanted it in rabbits. They found that glucose from the eye diffused through the material and fed the epithelial cells growing on the surface, which had been modified with collagen to promote cell growth. Sheardown is also developing a cornea made from two intertwined polymers. But it does not transport glucose as readily as Frank’s and she has not yet tested it on animals. Aria Pearson ● www.newscientist.com