: Photo: Dave Bullock/Wired.comLOS ANGELES -- UCLA scientists have developed a process for targeting cancer cells that could eliminate some of the worst side effects of chemotherapy. The new technique deploys nanoscale, light-activated containers filled with cancer-fighting drugs throughout the body. These containers release the drugs only when targeted by a special laser, allowing scientists to confine treatment only to desired areas of the body.
Normally in chemotherapy, the drugs are delivered to the whole body and attack healthy cells as well as the cancerous ones, which can be devastating to cancer patients. In a couple of years, these new nanomachines, called nanoimpellers, could help eliminate cancer in specific areas of a patient while the unused drugs pass through the body without affecting healthy tissue.
Click through the gallery to see the labs behind this process and time-lapse images of the nanoimpellers at work in real cancer cells.
Left: A sample of cancer cells infused with the nanoimpellers fills the bottom of a test tube in Dr. Fuyuhiko Tamanoi's lab in the Department of Microbiology, Immunology and Molecular Genetics at UCLA.
: Photo: Dave Bullock/Wired.comLeft: The nanoimpellers are created through a series of chemical reactions, using this lab equipment. No mechanical nanofabrication is required.
The nanoimpellers are contained in nanosize, sand-like particles which are covered with tiny holes. These holes are coated with a substance called azobenzene. When a very specific wavelength of light hits the azobenzene, it flexes and flaps tiny molecular arms. This motion pushes the cancer drugs out of the nanoimpeller and into the surrounding cell. The cancer cell, which unknowingly took the nanoonimpellers in, is then tricked into killing itself. Think of them as light-activated Trojan horses.
: Photo: Dave Bullock/Wired.comHere, the activating laser sits on an optic bench. If you look closely, you can see a blue light bouncing off a mirror in the center left of the photo. This is a laser with a wavelength of 413 nanometers, the exact wavelength needed to activate the nanoimpellers. Under the laser, the nanoimpellers flex and release the cancer-fighting medication directly inside the target area.
The UCLA researchers claim that the laser would be able to reach most skin cancer without surgery, but deeper tumors would require surgery in order to expose the cancerous tissue. Most cancer cells infused with the nanoimpellers die within a few minutes of exposure to the laser.
: Photo: Dave Bullock/Wired.comThe nanoimpellers are too small to observe directly without an electron microscope (see slides 9 and 10) so this optical microscope is used observe the effects the nanoimpellers have on the cancer cells (see next slide).
: Courtesy Jie Lu, Eunshil Choi, Fuyuhiko Tamanoi and Jeffrey I. Zink/Wiley Small 2008, 4, No. 4Figure A shows how cancer cells quickly die after absorbing the nanoimpellers and being exposed to the precisely calibrated laser (413 nm). Figure B shows how cells that are exposed to the light without the nanoimpellers, or with nanoimpellers but with no anti-cancer drug, end up living a happy cancerous life. Figure C shows untreated cells and cells infused with unactivated nanoimpellers in the dark.
: Photo: Dave Bullock/Wired.comDr. Jefferey Zink stands in the chemistry laboratory where the nanoimpellers are created.
A member of the California Nanosystems Institute, Zink is one of the authors of a recent paper on nanoimpellers. Zink has worked in the chemistry department of UCLA for almost 40 years and he is a widely recognized authority on nanomachines.
: Photo: Dave Bullock/Wired.comThis ventilated workbench is used to prepare living tissue samples for testing with the nanoimpellers. The samples containing the cancer cells and the nanoimpellers are then taken back to Zink's lab for blue-laser zapping.
: Photo: Dave Bullock/Wired.comVials filled with solutions containing billions of nanoimpellers cover a lab bench in the UCLA Zink Group laboratory.
: Photo: Dave Bullock/Wired.comA scanning electron microscope is used to image the nanoscale features of the nanoimpellers (see next slide).
: Courtesy Jie Lu, Eunshil Choi, Fuyuhiko Tamanoi and Jeffrey I. Zink/Wiley Small 2008, 4, No. 4Using a transmission electron microscope, we can see the sponge-like pores on the outside of the silica that contain the nanoimpellers (figure B and enlarged view on right). In figure A, a scanning electron microscope shows a zoomed-out view of three silica particles. Note that the actual nanoimpellers are too small to be imaged with either of these instruments.
: Photo: Dave Bullock/Wired.comThis X-ray diffraction scanner is used to image nanoscale crystalline structures like the ones that make up the nanoimpellers. The machine sends X-rays through a rotating sample and depending on the way they bend and scatter, the sample's structure can be determined. While the scanner does not produce an image, the physical configuration of the crystal can be reconstructed in software.
