Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
PZ HTL SA
GLOBETECH PUBLISHING LLC

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

New Program Encourages Wide Distribution of Genomic Data

A new data sharing program allows genomics researchers and practitioners to analyze, visualize, and share raw sequence data for individual patients or across populations straight from a local browser. The sequencing revolution is providing the raw data required to identify the genetic variants underlying rare diseases... Read more

Drug Discovery

view channel
Image: The nano-cocoon drug delivery system is biocompatible, specifically targets cancer cells, can carry a large drug load, and releases the drugs very quickly once inside the cancer cell. Ligands on the surface of the \"cocoon\" trick cancer cells into consuming it. Enzymes (the “worms\" in this image) inside the cocoon are unleashed once inside the cell, destroying the cocoon and releasing anticancer drugs into the cell (Photo courtesy of Dr. Zhen Gu, North Carolina State University).

Novel Anticancer Drug Delivery System Utilizes DNA-Based Nanocapsules

A novel DNA-based drug delivery system minimizes damage to normal tissues by utilizing the acidic microenvironment inside cancer cells to trigger the directed release of the anticancer drug doxorubicin (DOX).... Read more

Lab Technologies

view channel

Experimental Physicists Find Clues into How Radiotherapy Kills Cancer Cells

A new discovery in experimental physics has implications for a better determination of the process in which radiotherapy destroys cancer cells. Dr. Jason Greenwood from Queen’s University Belfast (Ireland) Center for Plasma Physics collaborated with scientists from Italy and Spain on the work on electrons, and published... Read more

Business

view channel

Interest in Commercial Applications for Proteomics Continues to Grow

Increasing interest in the field of proteomics has led to a series of agreements between private proteomic companies and academic institutions as well as deals between pharmaceutical companies and novel proteomics innovator biotech companies. Proteomics is the study of the structure and function of proteins.... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.