Rice University chemists have found a way to package some of nature's most powerful radioactive particles inside DNA-sized tubes of pure carbon -- a method they hope to use to target tiny tumors and even lone leukemia cells.
"There are no FDA-approved cancer therapies that employ alpha-particle radiation," said lead researcher Lon Wilson, professor of chemistry. "Approved therapies that use beta particles are not well-suited for treating cancer at the single-cell level because it takes thousands of beta particles to kill a lone cell. By contrast, cancer cells can be destroyed with just one direct hit from an alpha particle on a cell nucleus."
The study's results are available online and slated to appear in an upcoming issue of the journal Small.
In the study, Wilson, Rice graduate student Keith Hartman, University of Washington (UW) radiation oncologist Scott Wilbur and UW research scientist Donald Hamlin, developed and tested a process to load astatine atoms inside short sections of carbon nanotubes. Because astatine is the rarest naturally occurring element on Earth -- with less than a teaspoon estimated to exist in the Earth's crust at any given time -- the research was conducted using astatine created in a UW cyclotron.
Astatine, like radium and uranium, emits alpha particles via radioactive decay. Alpha particles, which contain two protons and two neutrons, are the most massive particles emitted as radiation. They are about 4,000 times more massive than the electrons emitted by beta decay -- the type of radiation most commonly used to treat cancer.
"It's something like the difference between a cannon shell and a BB," Wilson said. "The extra mass increases the amount of damage alpha particles can inflict on cancer cells."
The speed of radioactive particles is also an important factor in medical use. Beta particles travel very fast. This, combined with their small size, gives them significant penetrating power. In cancer treatment, for example, beams of beta particles can be created outside the patient's body and directed at tumors. Alpha particles move much more slowly, and because they are also massive, they have very little penetrating power. They can be stopped by something as flimsy as tissue paper.
"The unique combination of low penetrating power and large particle mass make alpha particle ideal for targeting cancer at the single-cell level," Wilson said. "The difficulty in developing ways to use them to treat cancer has come in finding ways to deliver them quickly and directly to the cancer site."
In prior work, Wilson and colleagues developed techniques to attach antibodies to carbon fullerenes like nanotubes. Antibodies are proteins produced by white blood cells. Each antibody is designed to recognize and bind only with a specific antigen, and doctors have identified a host of cancer-specific antibodies that can be used to kill cancer cells.
In follow-up research, Wilson hopes to test the single-celled cancer targeting approach by attaching cancer-specific antibodies to astatine-loaded nanotubes.
One complicating factor in any astatine-based cancer therapy will be the element's short, 7.5-hour half-life. In radioactive decay, the term half-life refers to the time required for any quantity of a substance to decay by half its initial mass. Due to astatine's brief half-life, any treatment must be delivered in a timely way, before the particles lose their potency.
Jade Boyd | EurekAlert!
Polymers Based on Boron?
18.01.2018 | Julius-Maximilians-Universität Würzburg
Bioengineered soft microfibers improve T-cell production
18.01.2018 | Columbia University School of Engineering and Applied Science
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
18.01.2018 | Life Sciences
18.01.2018 | Life Sciences
18.01.2018 | Earth Sciences