Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING
GLOBETECH PUBLISHING
JIB

Nontoxic Molecule Able to Store Radiation Securely

By BiotechDaily International staff writers
Posted on 16 Apr 2014
Image: John Tomich and his research lab team at Kansas State University combined two related sequences of amino acids to form a very small, hollow nanocapsule similar to a bubble (Photo courtesy of Kansas State University).
Image: John Tomich and his research lab team at Kansas State University combined two related sequences of amino acids to form a very small, hollow nanocapsule similar to a bubble (Photo courtesy of Kansas State University).
Image: The Kansas State University-developed nanocapsules safely store harmful daughter ions that are released from alpha particle radiation therapies (Photo courtesy of Kansas State University).
Image: The Kansas State University-developed nanocapsules safely store harmful daughter ions that are released from alpha particle radiation therapies (Photo courtesy of Kansas State University).
Microscopic “bubbles” have been found to be safe and effective storage lockers for harmful isotopes that emit ionizing radiation for treating tumors.

The findings can benefit patient health and advance radiation therapy used to treat cancer and other diseases, according to John M. Tomich, a professor of biochemistry and molecular biophysics who is affiliated with the Kansas State University’s (Manhattan, USA) Johnson Cancer Research Center.

Prof. Tomich conducted the study with Dr. Ekaterina Dadachova, a radiochemistry specialist at Albert Einstein College of Medicine (New York, NY, USA), along with researchers from Japan and Germany. They recently published their findings in the study ahead of print February 22, 2014, in the journal Biochimica et Biophysica Acta.

The study looks at the ability of nontoxic molecules to store and deliver potentially harmful alpha emitting radioisotopes—one of the most effective forms of radiation therapy.

In 2012, Prof. Tomich and his research lab team combined two related sequences of amino acids to form a very small, hollow nanocapsule similar to a bubble. “We found that the two sequences come together to form a thin membrane that assembled into little spheres, which we call capsules,” Prof. Tomich said. “While other vesicles have been created from lipids, most are much less stable and break down. Ours are like stones, though. They're incredibly stable and are not destroyed by cells in the body.”

The ability of the capsules to stay intact with the isotope inside and remain undetected by the body’s clearance systems prompted Prof. Tomich to investigate using the capsules as unbreakable storage containers that can be used for biomedical research, particularly in radiation therapies. “The problem with current alpha-particle radiation therapies used to treat cancer is that they lead to the release of nontargeted radioactive daughter ions into the body,” Dr. Tomich said. “Radioactive atoms break down to form new atoms, called daughter ions, with the release of some form of energy or energetic particles. Alpha emitters give off an energetic particle that comes off at nearly the speed of light.”

These particles are like a car sliding on ice, according to Prof. Tomich. They are very powerful but can only travel a short distance. The alpha particle destroys DNA when they collide and whatever critical cellular pieces are in its way. Similarly, the daughter ions recoil with high energy on ejection of the alpha particle—similar to how a gun recoils as it is fired. The daughter ions have enough energy to escape the targeting and containment molecules that currently are in use.

“Once freed, the daughter isotopes can end up in places you don’t want them, like bone marrow, which can then lead to leukemia and new challenges,” Dr. Tomich said. “We don’t want any stray isotopes because they can harm the body. The trick is to get the radioactive isotopes into and contained in just diseases cells where they can work their magic.”

The radioactive compound that the scientists work with is 225Ac (Actinium), which on decay releases four alpha particles and numerous daughter ions. Drs. Tomich and Dadachova tested the retention and biodistribution of alpha-emitting particles trapped inside the peptide capsules in cells. The capsules readily enter cells; once inside, they migrate to a position next to the nucleus, where the DNA resides.

Drs. Tomich and Dadachova found that as the alpha particle-emitting isotopes decayed, the recoiled daughter ion collides with the capsule walls and essentially bounces off them and remains trapped inside the capsule. This completely blocked the release of the daughter ions, which prevented uptake in certain nontarget tissues and protected the subject from harmful radiation that would have otherwise have been releases into the body.

Dr. Tomich stressed that more studies are needed to add target molecules to the surface of the capsules. He foresees that this new approach will provide a safer option for treating tumors with radiation therapy by reducing the amount of radioisotope required for destroying the cancer cells and reducing the side effects caused by off-target accumulation of the radioisotopes. “These capsules are easy to make and easy to work with,” Dr. Tomich said. “I think we’re just scratching the surface of what we can do with them to improve human health and nanomaterials.”

Related Links:

Kansas State University
Albert Einstein College of Medicine



comments powered by Disqus

Channels

Genomics/Proteomics

view channel
Image: Alternative splicing produces two protein isoforms (Photo courtesy of Wikimedia Commons).

Key Regulator of Cancer-Inducing Alternative Splicing Identified

Cancer researchers have identified the splicing factor RBM4 (RNA-binding protein 4) as a key determinant in processes that prevent tumor development and spread. RBM4 is known to be crucial to gene splicing... Read more

Drug Discovery

view channel

Ibuprofen May Restore Immune Function in Older Individuals

New research suggests that macrophages from the lungs of old mice respond differently to infections than those of young mice, and ibuprofen given to the mice reversed these changes. New research using lab mice suggests that the solution to more youthful immune function might already be a common over-the-counter pain reliever.... Read more

Therapeutics

view channel
Image: Hair follicle (blue) being attacked by T cells (green) (Photo courtesy of Christiano Lab/Columbia University Medical Center).

Hair Restoration Method Clones Patients’ Cells to Grow New Hair Follicles

Researchers have developed of a new hair restoration approach that uses a patient’s cells to grow new hair follicles. In addition, the [US] Food and Drugs Administration (FDA) recently approved a new drug... Read more

Lab Technologies

view channel
Image: Leica Microsystems launches the inverted research microscope platform Leica DMi8 (Photo courtesy of Leica Microsystems).

New Inverted Microscope Designed to Readily Adapt to Changing Research Demands

A new inverted microscope for biotech and other life science laboratories was designed to readily accommodate modifications and upgrades to allow it to keep current with changing research demands and interests.... Read more

Business

view channel

Partnership Established to Decode Bowel Disease

23andMe (Mountain View, CA,USA), a personal genetics company, is collaborating with Pfizer, Inc. (New York, NY, USA), in which the companies will seek to enroll 10,000 people with inflammatory bowel disease (IBD) in a research project designed to explore the genetic factors associated with the onset, progression, severity,... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.