Nanoparticles on track to distinguish tumour tissue

May 22, 2014 by Chris Thomas
Nanoparticles could be used with optical coherence tomography (OCT) tests to help surgeons distinguish the tumour from other tissue. Credit: US Department of Defence, Kristopher Radder

Gold nanoparticles could be used to help detect the margins between tumours and normal tissue, enabling surgeons to better determine which tissue to remove and which to leave.

Research by Jeremy Duczynski from the University of WA's School of Chemistry and Biochemistry investigated whether the nanoparticles would work as effective optical contrast agents to provide an estimate of the size and shape of tumour margins during surgery.

Optical coherence tomography (OCT) is a recently developed high-resolution imaging test but one of its limitations is an inability to distinguish between some types of healthy and tumours.

Other imaging tests use dye administered to patients to distinguish between different tissue types—although, to date, no such dyes exist for OCT.

Mr Duczynski says OCT is analogous to ultrasound, using light instead of sound waves for detection.

"The problem is the and absorbing qualities of tumour tissue can be quite similar to healthy tissue," he says.

"This is why different agents are being pursued to increase this contrast.

"Most research has been done with straight as contrast agents but the problem with them is they absorb light very strongly. This leads to negative contrast with the image appearing darker in areas with gold.

"This is a problem because empty spaces, such as the thoracic cavity, will also appear dark, possibly leading to incorrect identification of tumour margins."

Silica-gold nanoparticles provide greater contrast, visibility

To get around this, Mr Duczynski used coated with a gold shell (silica-gold core-shell nanoparticles) in his research.

"There are some theoretical and experimental papers where it was observed that by varying the dimensions of either the silica core or gold shell you could also vary the scattering ratio of the particles," he says.

"This makes them possible for OCT because the test requires a high scattering of light at about 850 nanometres for good image contrast."

Ultra-violet spectroscopy was used on the silica-gold core-shell nanoparticles made by Mr Duczynski to better understand their optical properties, such as extinction, scattering and absorption.

The research also involved the development of iron oxide-gold core shell nanoparticles.

"This particle system was attempted because I was having difficulty with shelling the silica particles," Mr Duczynski says.

"I was able to see some scattering of the iron oxide-gold core-shell nanoparticles, meaning they could possibly be pursued as another contrast agent for OCT.

"Iron oxide is also magnetic, meaning these particles could be used as a multimodal contrast agent for imaging techniques such as MRI [magnetic resonance imaging]."

Explore further: Highlight: Superparamagnetic Gold Nanoshells with Tunable Optical Properties

Related Stories

Two-in-one imaging agents

March 19, 2012

(PhysOrg.com) -- Accurate visualization of living systems is key to the correct diagnosis and effective treatment of many diseases, as well as an improved understanding of biological processes. Magnetic resonance imaging ...

Hot nanoparticles for cancer treatments

March 24, 2014

Nanoparticles have a great deal of potential in medicine: for diagnostics, as a vehicle for active substances or a tool to kill off tumours using heat. ETH Zurich researchers have now developed particles that are relatively ...

Gold nanoparticles for cancer treatment

May 13, 2014

A new project at the National Physical Laboratory (NPL) will develop methodologies to measure the radio-biological impact of gold nanoparticles, when used in combination with ionising radiation for enhancing radiotherapy ...

Recommended for you

New nanomaterial maintains conductivity in 3-D

September 4, 2015

An international team of scientists has developed what may be the first one-step process for making seamless carbon-based nanomaterials that possess superior thermal, electrical and mechanical properties in three dimensions.

Graphene made superconductive by doping with lithium atoms

September 2, 2015

(Phys.org)—A team of researchers from Germany and Canada has found a way to make graphene superconductive—by doping it with lithium atoms. In their paper they have uploaded to the preprint server arXiv, the team describes ...

Making nanowires from protein and DNA

September 3, 2015

The ability to custom design biological materials such as protein and DNA opens up technological possibilities that were unimaginable just a few decades ago. For example, synthetic structures made of DNA could one day be ...

For 2-D boron, it's all about that base

September 2, 2015

Rice University scientists have theoretically determined that the properties of atom-thick sheets of boron depend on where those atoms land.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.