Wednesday, February 07, 2007
Self-assembling gel stops bleeding in seconds
- 13:15 10 October 2006
- NewScientist.com news service
- Robert Adler
Swab a clear liquid onto a gaping wound and watch the bleeding stop in seconds. An international team of researchers has accomplished just that in animals, using a solution of protein molecules that self-organise on the nanoscale into a biodegradable gel that stops bleeding.
If the material works as well in humans, it could save thousands of lives and make surgery far easier in many cases, surgeons say.
Molecular biologist Shuguang Zhang, at the Massachusetts Institute of Technology in the US, began experimenting with peptides in 1991. Zhang and colleagues at MIT and the University of Hong Kong in China went on to design several materials that self-assemble into novel nano-structures, including a molecular scaffold that helps the regrowth of severed nerve cells in hamsters (see Nano-scaffolds could help rebuild sight).
Their work exploits the way certain peptide sequences can be made to self-assemble into mesh-like sheets of "nanofibres" when immersed in salt solutions.
In the course of that research they discovered one material's dramatic ability to stop bleeding in the brain and began testing it on a variety of other organs and tissues. When applied to a wound, the peptides form a gel that seals over the wound, without causing harm to any nearby cells.
Vessels and arteries
"In rodents it works in all the blood vessels and arteries, including the femoral artery, the portal vein, and in the liver," says MIT neuroscientist Rutledge Ellis-Behnke.
The peptides assemble into a gel that looks "like a hairy ribbon, but at the nanoscale" says Ellis-Behnke, although precisely how it stops bleeding is not yet clear. "It's critically important to understand the mechanism so we can rationally design new self-assembling materials," Zhang says.
Some surgeons are already excited about the material. "I see great potential in the eye field, the gastro-intestinal field, and in neurosurgery," says Dimitri Azar, head of ophthalmology at the University of Illinois at Chicago, US.
Paradigm shift
"In the eye, even a drop of blood will blur your vision for a long time," Azar adds. "A material that would stop the bleeding could lead to a paradigm shift in how we practice surgery in the eye."
Ed Buchel, who teaches general and plastic surgery at the University of Manitoba, in Winnipeg, Canada, sees equal potential for treating trauma and burns. "If this works as well on humans as it does on rats, it's phenomenal," he says.
Still, they caution that extensive clinical trials are needed to make sure the materials work properly and are safe. The MIT researchers hope to see those crucial human trials within three to five years.
Their research will appear in the 10 October 2006 edition of online journal Nanomedicine.
Saturday, February 03, 2007
Indian Organ Mafia Busted
Police have begun to make arrests in tightly knit ring of organ smugglers who have been operating in Tamil Nadu, India for the last two to ten years. In the last month there have been a slew of media reports about the organ racket, and while many of the details are still a bit fuzzy the implications are clear.
The first reports came during a public meeting of disenfranchised tsunami survivors in the village of Eranavoor who were airing their disappointment with government efforts to find them shelter and alleviate some of the more crushing aspects of poverty. In that meeting a group of 35 women admitted to having sold their kidneys to brokers and that they were put up in posh hospitals in nearby Chennai for a few days before being cast out on the street without after care. They women were primarily upset because the brokers offered them large sums of money, but ended up cheating them out of the lions share of the rewards.
Since the initial report over 150 people have come forward as victims of kidney brokers. Police from around the state are estimating that the total number of illegal transplants edges closer to 500. There have also been reports that some of the brokers also dealt in liver and bone marrow.
Other reports have suggested that many of the buyers are medical tourists from the middle east who have come to Chennai in order to skip over lengthy waiting lists in their home country while also saving a great deal of money on the surgery.
More after the jump...
The police have already begun investigations into some of the hospitals that preformed the operations, yet the magnitude of the racket threatens to destabilize the medical administrations across the state. After a slew of illegal transplants in the 1990s, the government issued a law making it illegal to perform an operation without a thorough review from an ethics board.
The rules specifically state that no transplant should be undertaken if there is payment involved, and that all live transplants should be donations, preferably from family members. The organ mafia seems to have been able to provide false documents for the would be patients.
But it now appears that the state level ethics committee chaired by the Director of Medical Education in Chennai was complicit in the illegal dealings and authorized surgeries that they knew were about to be preformed under sham circumstances.
As one reporter I spoke to today said, "The ethics board would have to have been mad to think that all of these people flying in from around the country for transplants had poor, illiterate tsunami survivors for relatives living in the vicinity of the hospitals." Members of the local ethics boards maintain that they did nothing wrong.
Labels: medical crime organ_piracy