Magnetic fluorescent nanoparticles highlight brain tumours for MRI
7 May 2010
Scientists at Ohio State University have combined two types of
nanoparticle to create a 'nanocomposite' that is both magnetic and
The magnetic nanoparticle emphasizes colour contrasts within
magnetic resonance imaging (MRI), allowing doctors to see potential
or existing cancerous tumours before surgery. The fluorescent
nanoparticle can change the colour that the tumour appears in the
brain when seen under a special light during surgery.
“Our strategy is combining two particles that contain different
properties to make one particle with multiple properties,” explained
Jessica Winter, assistant professor in chemical and biomolecular
engineering and biomedical engineering at Ohio State.
“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
tumour and it will glow a specific colour such as green, for
example. Then, the surgeon can simply remove all of the green,”
Winter said. “With traditional magnetic contrasting agents, you’ll
get an MRI, but you won’t see anything during surgery."
Winter’s study provided convincing proof that a particle with
dual properties can be formed. However, these multi-functional
particles can’t 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,” Winter
Patients with a specific form of deadly brain tumour,
glioblastoma, could benefit from Winter’s work. Glioblastomas are
usually located in the temporal, or frontal lobe of the brain, and
tumours located there are difficult to see and remove.
Combining the two particles could provide doctors with help both
before and during the surgery to remove a brain tumour, Winter said.
One of the successes in creating the new nanocomposite particle
was how they did it, Winter said. It is normally difficult to
combine particles like these, a process known as doping.
The Ohio State researchers pursued an approach which had not been
attempted 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 degrees Celsius,” Winter explained. “The
synthesis was unexpected, but cool at the same time, and we were
excited when we saw what we got.”
The primary neurological surgeon that collaborates with Winter
and her team, an assistant professor with the Department of
Neurological Surgery, Atom Sarkar, hopes to test the approach on
animals at some point. But first they have to produce a particle
that contains no toxic ingredients. If results continue to be
encouraging, Winter is optimistic that similar multifunctional
particles could become an innovative part of neurological surgery
within the next five years.