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Canadian researchers say they have found a solution to the humble condom’s fatal flaw: nanoparticles.
Condoms have a 15% failure rate, so a University of Manitoba team tried soaking condoms in a solution packed with “remarkable,” microscopic silver nanoparticles, and the treated devices appeared to kill all HIV and herpes in lab experiments, the scientists report.
“Till now, there has been no single condom with additional protection against sexually transmitted infections available on the market,” noted the group’s paper just published in the International Journal of Nanotechnology. But when their novel nanoparticle condoms contacted HIV, “the infectiousness of the virus could be completely inactivated.”
It has long been known that silver has disinfectant powers, prompting people in the early 1900s to put it in milk to stave off spoilage, and in eye drops to try to prevent infection. Its effectiveness, though, was less than reliable.
The new technology has changed that. Nanoparticles are tiny clusters of atoms created by scientists, so small that it would take thousands of them to equal the dimensions of a human red-blood cell. The unique qualities that nano-sizing gives to substances are the subject of intense study in a number of fields, and many of the particles are already used in consumer products ranging from scratch-resistant eyeglasses to better-gripping car tires.
When silver is turned into nano-sized bits, it seems to become more effective at combating bacteria and viruses, said Dr. Xiaojian Yao, lead author of the study. “At such nanoscale, the extremely small size of silver particles exhibits remarkable, unusual physio-chemical properties and biolgical activity,” he said.
Their tiny dimensions also mean they can be plastered on something like a polyurethane condom without changing its size or shape.
Yet how, exactly, the silver nanoparticles neutralize HIV and other viruses is still a bit of mystery. It could be the particles or the silver ions they release attach to the virus and prevent it from binding to cell “receptors” in the host’s body, said Dr. Yao, a medical microbiologist. Or they could actually change a key protein on the virus’s surface, and in that way stop it from sticking to host cells. Some condoms are now treated with an anti-microbial substance, called Nonoxynol-9. Recent studies, though, have shown that N-9 can trigger inflammation and ulceration in the genitals, actually making infection more likely.
The silver nanoparticles do not cause inflammation, said Dr. Yao. And the nano-treated condoms have the added advantage of being quickly discarded, meaning the potentially toxic metal does not linger in users’ bodies, the study notes.
The research is still in its early stages, however, with animal studies on the nanoparticle contraceptives the next step, and possible entry on the market relatively far off.
Dr. Julio Montaner, one of Canada’s leading HIV scientists, said the idea is “intriguing” and welcome in the field.
Meanwhile, though, the most significant problem with condoms is not the 15% that fail to prevent STIs, but the fact many people simply neglect to use them, said the head of the B.C. Centre for Excellence in HIV/AIDS.
“Unfortunately, at the most critical moment when these decisions are so important, people’s judgment may be impaired,” said Dr. Montaner. “At the end of the day, if they stay in the pocket, it’s not going to do the job.”
As well as providing extra protection to sexual partners when a condom fails, nanotechnology could have other benefits, too, said Dr. Yao. There are reports from developing countries such as India of children and others finding and touching used condoms, then contracting STIs, he said. Treated with nanosilver, the chances of discarded condoms infecting anyone might be greatly reduced.
http://news.nationalpost.com/2012/1...letely-inactivate-hiv-other-stds-researchers/
Condoms have a 15% failure rate, so a University of Manitoba team tried soaking condoms in a solution packed with “remarkable,” microscopic silver nanoparticles, and the treated devices appeared to kill all HIV and herpes in lab experiments, the scientists report.
“Till now, there has been no single condom with additional protection against sexually transmitted infections available on the market,” noted the group’s paper just published in the International Journal of Nanotechnology. But when their novel nanoparticle condoms contacted HIV, “the infectiousness of the virus could be completely inactivated.”
It has long been known that silver has disinfectant powers, prompting people in the early 1900s to put it in milk to stave off spoilage, and in eye drops to try to prevent infection. Its effectiveness, though, was less than reliable.
The new technology has changed that. Nanoparticles are tiny clusters of atoms created by scientists, so small that it would take thousands of them to equal the dimensions of a human red-blood cell. The unique qualities that nano-sizing gives to substances are the subject of intense study in a number of fields, and many of the particles are already used in consumer products ranging from scratch-resistant eyeglasses to better-gripping car tires.
When silver is turned into nano-sized bits, it seems to become more effective at combating bacteria and viruses, said Dr. Xiaojian Yao, lead author of the study. “At such nanoscale, the extremely small size of silver particles exhibits remarkable, unusual physio-chemical properties and biolgical activity,” he said.
Their tiny dimensions also mean they can be plastered on something like a polyurethane condom without changing its size or shape.
Yet how, exactly, the silver nanoparticles neutralize HIV and other viruses is still a bit of mystery. It could be the particles or the silver ions they release attach to the virus and prevent it from binding to cell “receptors” in the host’s body, said Dr. Yao, a medical microbiologist. Or they could actually change a key protein on the virus’s surface, and in that way stop it from sticking to host cells. Some condoms are now treated with an anti-microbial substance, called Nonoxynol-9. Recent studies, though, have shown that N-9 can trigger inflammation and ulceration in the genitals, actually making infection more likely.
The silver nanoparticles do not cause inflammation, said Dr. Yao. And the nano-treated condoms have the added advantage of being quickly discarded, meaning the potentially toxic metal does not linger in users’ bodies, the study notes.
The research is still in its early stages, however, with animal studies on the nanoparticle contraceptives the next step, and possible entry on the market relatively far off.
Dr. Julio Montaner, one of Canada’s leading HIV scientists, said the idea is “intriguing” and welcome in the field.
Meanwhile, though, the most significant problem with condoms is not the 15% that fail to prevent STIs, but the fact many people simply neglect to use them, said the head of the B.C. Centre for Excellence in HIV/AIDS.
“Unfortunately, at the most critical moment when these decisions are so important, people’s judgment may be impaired,” said Dr. Montaner. “At the end of the day, if they stay in the pocket, it’s not going to do the job.”
As well as providing extra protection to sexual partners when a condom fails, nanotechnology could have other benefits, too, said Dr. Yao. There are reports from developing countries such as India of children and others finding and touching used condoms, then contracting STIs, he said. Treated with nanosilver, the chances of discarded condoms infecting anyone might be greatly reduced.
http://news.nationalpost.com/2012/1...letely-inactivate-hiv-other-stds-researchers/
