[ti:Researchers May Have Found New Weapon Against Disease] [by:www.sp636.com] [00:00.00]更多聽力請訪問51VOA.COM [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 我要操