[ti:Researchers May Have Found New Weapon Against Disease]
[00:00.01]Some bacteria have grown so strong that they cannot be killed with antibiotic drugs.
[00:09.40]Medical experts call them antibiotic-resistant bacteria.
[00:15.32]The World Health Organization says antibiotic-resistant bacteria are one of the biggest threats to human health.
[00:25.82]But, researchers now say they may have found a way to fight them.
[00:31.83]A team of researchers from three universities is working on a cell-killing "machine" that is too small for the human eye to see.
[00:43.53]"We want to be bacteria's worst nightmare."
[00:47.41]That was James Tour, a member of the team.
[00:52.24]Tour is a chemistry professor at Rice University in Houston.
[00:58.63]He is also a professor of materials science and nanoengineering and computer science.
[01:07.61]In addition to Rice University, the researchers come from Durham University in Britain and North Carolina State University.
[01:17.83]The team is experimenting with very small nanomachines that can drill into a cell and kill it.
[01:27.63]These "machines" are really single molecules that can rotate about three million times a second when near-infrared light shines on them.
[01:41.28]Tour said harmful bacteria cannot defeat this kind of weapon by changing and growing stronger.
[01:50.71]"We may have found something that the cell could never build a resistance to."
[01:56.33]The team's work is based on the Nobel-prize winning designs of other scientists.
[02:04.48]In 2016, three researchers received the Nobel Prize in Chemistry for creating the first nanomachines.
[02:15.09]But the team's cell-killing nanomachines are much smaller.
[02:20.73]About 50,000 of them can fit across the width of a human hair.
[02:27.21]In comparison, only about 50 cells can fit in that amount of space.
[02:33.69]The nanomachines could also be effective against another serious health problem: cancer.
[02:42.95]The machines can drill into cancer cells, causing the cells' center to break into pieces.
[02:52.38]Tour said the team has tried four different kinds of cancer cells, and the nanomachines killed all of them.
[03:02.02]The team carried out the tests on two kinds of human breast cancer cells, cancerous skin cells and pancreatic cancer cells.
[03:13.90]The way it works is that a peptide, another kind of molecule, is added to the nano-drill.
[03:21.92]That peptide recognizes a diseased cell and attaches the nanomachine to it.
[03:29.90]Then, a special light activates the machine which drills into and kills the cell.
[03:38.10]Tour said many nanomachines work together against the diseased cells.
[03:45.11]"Generally, it's not just one nanomachine, it's, it's 50, and each cell is going to get 50 holes drilled in it."
[03:54.73]The nanomachines can fight cancer cells in the mouth, upper and lower gastrointestinal areas,
[04:03.48]bladder and other body parts where light can be shined to start the engines, Tour said.
[04:11.33]It would only take a few minutes to kill cancer cells with nanomachines, Tour added.
[04:19.36]He noted that radiation and chemotherapy take much longer.
[04:26.10]In addition to killing bacteria and cancer cells, nanomachines might be used to kill fat cells when placed onto the skin with a gel.
[04:39.19]Tour said, when you pass the bright light over the problem areas, the machines attack the fat cells.
[04:48.43]Researchers have only worked with nanomachines in the laboratory.
[04:54.84]They say using this technology in studies on humans is still some time away.
[05:03.29]Later this year, researchers will start testing nanomachines on bacterial skin infections on live animals.
[05:13.16]As research continues, one problem scientists will have to solve is how to get the light deep into some parts of the body.
[05:24.40]This would permit the engines to fight bacteria or cancers far below the surface of tissue.
[05:33.94]I'm Alice Bryant. 更多聽力請訪問51VOA.COM