Nanoparticles May Help Surgeons by Tagging Brain Tumors

Researchers have developed a way to enhance how brain tumors appear on magnetic resonance imaging (MRI) scans and during surgery, making the tumors easier for surgeons to identify and remove.

Scientists from Ohio State University (Columbus, USA) are experimenting with different nanoparticles that they hope may one day be injected into the blood of patients and help surgeons remove lethal brain tumors known as glioblastomas.

In the April 9, 2010, issue of the journal Nanotechnology, researchers reported that they have manufactured a small particle called a nanocomposite that is both magnetic and fluorescent. These nanocomposites measure less than 20 nm in size. "Our strategy is combining two particles that contain different properties to make one particle with multiple properties,” explained Dr. Jessica Winter, assistant professor in chemical and biomolecular engineering and biomedical engineering at Ohio State.

The magnetic nanoparticles highlight color contrasts within MRI scans, allowing clinicians to see potential or existing cancerous tumors before surgery. The fluorescent nanoparticles can change the color that the tumor appears in the brain when seen under a special light.

Neurologic surgeons could benefit from a multifunctional particle that would allow them to better see the tumor with an MRI before surgery, and then see it physically during surgery, according to Dr. Winter. "We're trying to develop a single nanocomposite that's magnetic--so you can do preoperative MRI--and that's fluorescent--so that when neurological surgeons go into surgery, they can shine a light on the tumor and it will glow a specific color such as green, for example. Then, the surgeon can simply remove all of the green,” Dr. Winter stated.

Dr. Winter's study provided convincing proof that a particle with dual properties can be formed. However, these multifunctional particles cannot be used for animal or human testing because the fluorescent particle, cadmium telluride, is toxic. "We're currently working on an alternative fluorescent particle which is composed of carbon. This will eliminate the complications that arise with ingesting the cadmium telluride particles,” Dr. Winter said.

One of the successes in creating the new nanocomposite particle was how they did it, Dr. Winter noted. It is typically difficult to combine particles such as these, a process known as doping. The Ohio State researchers pursued an approach, which had not been tried before. They chose to bind their fluorescent particle on top of their magnetic particle at extremely high temperatures.

"The key is that our synthesis is done at pretty high temperatures--about 350 ^oC Dr. Winter explained. "The synthesis was unexpected, but cool at the same time, and we were excited when we saw what we got.”

The lead neurologic surgeon that collaborates with Dr. Winter and her team, an assistant professor with the department of neurological surgery, Dr. Atom Sarkar, hopes to assess the application on animals at some point. First, they have to produce a particle that contains no toxic ingredients. If results continue to be encouraging, Dr. Winter is optimistic that similar multifunctional particles could become an innovative part of neurologic surgery within the next five years.

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