Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers developing new arsenal in war against cancer

16.12.2002


In the battle against cancer, Virginia Tech researchers have developed a potential warhead to better kill cancer cells, a new missile to deliver the warhead more efficiently to the diseased areas, and a new detonation device once the warhead is in place.



In a cross-disciplinary effort, the researchers, using photodynamic therapy (PDT), have obtained results in three different areas that, used together, have the possibility of providing more efficient, less invasive, and more specific treatments for cancer and other diseases such as age-related macular-degeneration.

A long-term concept has held that one should be able to use light-activated compounds to kill diseased cells, said Karen Brewer, associate professor of chemistry. The researchers have developed new tri-metallic supra-molecules that can be positioned in exact parts of cancer cells and excited by a therapeutic wavelength at which light propagates efficiently through tissue. Only when the light hits the supra-molecules do they become toxic to the cancer cells.


The advantages are many. The non-surgical process avoids the debilitating side effects of normal chemotherapy. The system enables the scientists to place the supra-molecules at specific locations in cells and to deliver light activating the cancer-killing molecules directly at that spot in a strength that does not harm other tissue. "This allows much lower dosages of light to be effective, so we can use agents that are more aggressive and not get the side effects of chemotherapy," Brewer said.

Researchers Shawn Swavey and Alvin Holder, along with students Lee Williams and Nathan Toft, working in the Brewer laboratory, developed the new mixed-metal supra-molecular complexes (medicines) that Brewer and Brenda Winkel, professor of biology, have proven are capable of photo-cleaving DNA, a normal therapeutic target in cells. The complexes are novel molecules whose chemistry allows the researchers to append them to other units.

At present, physicians use a chemical that is exposed to light and activates oxygen in photodynamic therapy. In tumor cells, oxygen is depleted rapidly, so those treatments can run out of oxygen and not kill the entire tumor, which can return. Brewer’s new systems don’t need oxygen, and the researchers can change the wavelength of light used. "We can fine tune the compound for light-absorbing characteristics," Brewer said. "By using a lower energy, we can better penetrate the body."

Brian Storrie, professor of biochemistry, and research scientist Maria Teresa Tarrago-Trani of biochemistry have developed the "rocket" with which to deliver the cancer-killing agents to particular organelles, or parts, in the cancer cells. "We have used a polypeptide that binds to a cell surface receptor, and that molecule is over-expressed for certain cancers. We can deliver photosynthesizers to the cancer," Storrie said.

The delivery vehicle is a B-fragment of a class of toxins known as shiga toxins. The A fragment is toxic, but the B fragment is a non-toxic delivery system. Storrie developed a way to use the B fragment to deliver the photo-dynamic agents developed by Brewer into the cells. This enables the researchers to target certain kinds of cancer cells that have receptors for the B fragment and deliver the agent to the exact spot in the cell so the supra-molecule can attack that part. This allows for the destruction of many parts in the cancerous cells.

Ken Meissner, senior research scientist with the Optical Science and Engineering Research (OSER) Center at Virginia Tech is developing the "detonation device" for the supra-molecules, which are nontoxic until hit by light. His specialty is the delivery of light to the correct tissues and to the supra-molecules positioned to kill the cells. Meissner develops better ways to get the light to the tumor and to understand how light passes through tissue

Together, the three-part attack opens up huge new areas for fighting cancer. "We can attach the delivery vehicles, change the light we need, change the biological target in the cells, and design a molecule that reacts with that part," Brewer said. In other words, Brewer can develop different molecules for different areas of the cells, Storrie can develop ways to get those molecules to the right places in the cells, and Meissner can develop methods to deliver the light needed to begin the killing of cancer cells. Or, Meissner can develop a new light-delivery system to work in a certain area, and then Brewer can develop a molecule that will kill tumor cells when excited with this light, and Storrie can get the molecule there.

The possibilities are greatly expanded by the variety of supra-molecules and the interactive work of these researchers. This exciting work is in the early stages, but the researchers hope it will someday be the basis for important strides in the treatment of cancer and other diseases.

The research is being done within the OSER Photodynamics Mini-center, a joint effort between the Carilion Biomedical Institute and Virginia Tech. Research groups collaborating under the mini-center include researchers Brewer, Storrie, Meissner, and Winkel, and Yannis Besieris and Brad Davis of electrical and computer engineering, Sun Young Kim of biochemistry, and Ed Wojcik of biology, all of Virginia Tech


Researcher contact information:
Karen Brewer 540-231-6579, kbrewer@vt.edu,
Brian Storrie 540-231-6434, storrie@vt.edu,
Ken Meissner 540-231-2512, cmeissne@vt.edu

PR CONTACT: Sally Harris 540-231-6759 slharris@vt.edu


Karen Brewer | EurekAlert!
Further information:
http://www.chem.vt.edu/chem-dept/brewer/brewer.html
http://www.biochem.vt.edu/faculty/storrie.html

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>