Novel nanozyme protects bones from radiation damage

Melanie Coathup and Sudipta Seal, University of Central Florida materials scientists, have developed a cerium oxide nanoparticle -; an artificial enzyme -; which protects the bones from radiation damage. The nanoparticle has also shown abilities to enhance bone regeneration, reduce blood cell loss, and kill cancer cells.

Their study, a collaboration with Oakland University, North Carolina A&T University, the University of Sheffield and the University of Huddersfield in the UK, was published in Bioactive Materials.

About 50% of all cancer patients receive radiation therapy -; a treatment that uses electrically charged particles to kill cancer cells. About 40% of patients are cured with this therapy. However, bone damage is a side effect affecting approximately 75% of patients receiving radiation.

“Because of its high calcium content, bone absorbs 30-40% more radiation than other tissues and is therefore a common site of injury,” says Coathup, director of UCF’s Biionix faculty cluster. “Radiation makes bone brittle and breaks easily. And because of the damage caused by radiation, many people are then unable to repair their broken bones. In some people, this leads to amputation to correct the complication.”

While radiation therapy rays are aimed directly at the tumor, surrounding healthy tissue is also damaged and can cause many additional health problems for patients.

Currently, there is no real drug or therapy to protect healthy tissue from radiation damage. This is not only a problem for cancer patients undergoing radiation therapy, but also poses problems for astronauts and future space exploration.”


Melanie Coathup, University of Central Florida

The body’s natural defense against radiation is a group of enzymes called antioxidants -; However, this defense system is easily overwhelmed by radiation and alone cannot protect the body from damage. Seal, a leading nanotechnologist, designed the cerium oxide nanoparticle -; or nanoceria -; which mimics the activity of these antioxidants and has a stronger defense mechanism to protect cells from DNA damage.

“The Nanoceria works with a specially designed regenerative lattice structure that is responsible for destroying harmful reactive oxygen species, a by-product of radiation treatment,” says Seal.

Working with postdoc Fei Wei, Coathup tested the nanozyme in living models receiving radiation therapy.

“Our study showed that exposure of rats to radiation levels similar to those in cancer patients resulted in weak and damaged bones,” says Coathup. ‘However, when we treated the animals with the nanozyme before and during three doses of radiation over three days, we found that the bone was not damaged and had a strength similar to healthy bone.’

The study also showed that Nanozyme treatment helped kill cancer cells, possibly due to an increase in acidity, and protected against the loss of white and red blood cells that normally occurs in cancer patients. A low white and red blood cell count means the patient is more susceptible to opportunistic infections, is less able to fight cancer, and is more fatigued. Another interesting finding is that the nanoparticle also improved healthy cells’ ability to produce more antioxidants, reduced inflammation (which also leads to bone loss), and promoted bone formation.

Future research will attempt to determine the appropriate dosage and administration of the nanozyme and further investigate how nanozyme helps kill cancer cells. The researchers will also focus their studies in the context of breast cancer, since women are more prone to bone damage than men.

“Cancer patients are already struggling to fight a disease,” says Coathup. “You shouldn’t have to worry about broken bones and tissue damage. So we hope that this breakthrough will help survivors get back to normal and healthy lives.”

Coathup completed her undergraduate studies in medicinal cell biology and earned a Ph.D. in orthopedic implant fixation at University College London in the UK. In 2017, she joined the College of Medicine and became Director of UCF’s Biionix Faculty Cluster -; a multidisciplinary team of researchers working to develop innovative materials, processes and interfaces for advanced medical implants, tissue regeneration, prostheses and other future high-tech products.

Seal joined UCF’s Department of Materials Science and Engineering in 1997. He has tenure at the College of Medicine and is a member of UCF’s Biionix prosthetics cluster. He is the former director of UCF’s NanoScience Technology Center and Advanced Materials Processing Analysis Center. He received his PhD in materials engineering with a minor in biochemistry from the University of Wisconsin and was a postdoctoral fellow at the Lawrence Berkeley National Laboratory at the University of California, Berkeley.

Source:

Magazine reference:

Wei, F. et al. (2022) A novel approach to preventing ionizing radiation-induced bone loss using a designer multifunctional ceria nanozyme. Bioactive Materials. doi.org/10.1016/j.bioactmat.2022.09.011.

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