Nav: Home

Tiny super magnets could be the future of drug delivery

November 14, 2016

Microscopic crystals could soon be zipping drugs around your body, taking them to diseased organs. In the past, this was thought to be impossible - the crystals, which have special magnetic properties, were so small that scientists could not control their movement. But now a team of Chinese researchers has found the solution, and their discovery has opened new applications that could use these crystals to improve - and perhaps even save - many lives.

Kezheng Chen and Ji Ma from Quingdou University of Science and Technology, Quingdou, China have published a method of producing superparamagnetic crystals that are much larger than any that have been made before. They recently published their findings in Physics Letters A.

If some magnetic materials, such as iron oxides, are small enough - perhaps a few millionths of a millimeter across, smaller than most viruses - they have an unusual property: their magnetization randomly flips as the temperature changes.

By applying a magnetic field to these crystals, scientists can make them almost as strongly magnetic as ordinary fridge magnets. It might seem odd, but this is the strongest type of magnetism known. This phenomenon is called superparamagnetism.

In theory, superparamagnetic particles could be ideal for drug delivery, as they can be directed to a tumor simply by using a magnetic field. Their tiny size, however, has made them difficult to guide precisely - until now.

"The largest superparamagnetic materials that we have been able to make before now were clusters of nanocrystals that were together about a thousand times smaller than these," commented Dr. Chen. "These larger crystals are easier to control using external magnetic fields, and they will not aggregate when those fields are removed, which will make them much more useful in practical applications, including drug delivery."

Chen and Ma explained that the high temperature and pressure under which the crystals form made tiny meteorite-like 'micro-particles' of magnetite escape from their surface. This caused the unusual pock-marked appearance of the crystal surfaces and induced a high degree of stress and strain into the lattice of the growing crystals.

Crystals that grow under such high stresses and strains form with irregularities and defects in their crystal lattice, and it is these irregularities that are responsible for the unusual magnetic properties of Chen's crystals.

Magnetite crystals of a similar size that are grown at a lower temperature and under normal pressure are only very weakly magnetic.

This method of making larger superparamagnetic crystals paves the way for the development of superparamagnetic bulk materials that can be reliably controlled by moderate external magnetic forces, revolutionizing drug delivery to tumors and other sites in the body that need to be targeted precisely.

And this is just the beginning. Chen's crystals might, for example, be useful in the many engineering projects that need "smart fluids" that change their properties when a magnetic field is applied. These can already be used to make vehicle suspension systems that automatically adjust as road conditions change, increasing comfort and safety, and to build more comfortable and realistic prosthetic limbs.

Now that superparamagnetism is no longer restricted to minute particles that are difficult to handle, researchers can start exploring in which ways this can contribute to improving our lives.
-end-
Notes for editors

The article is "Discovery of superparamagnetism in sub-millimeter-sized magnetite porous single crystals," by Ji Ma and Kezheng Chen (doi:10.1016/j.physleta.2016.07.065 ). It appears in Physics Letters A, volume 380, issue 41 (2016), published by Elsevier.

This paper is available for free download on until 1 May 2017.

About Physics Letters A

Physics Letters A offers an exciting publication outlet for novel and frontier physics. It encourages the submission of new research on: condensed matter physics, theoretical physics, nonlinear science, statistical physics, mathematical and computational physics, general and cross-disciplinary physics (including foundations), atomic, molecular and cluster physics, plasma and fluid physics, optical physics, biological physics and nanoscience.

About Elsevier

Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions -- among them ScienceDirect, Scopus, Research Intelligence and ClinicalKey-- and publishes over 2,500 journals, including The Lancet and Cell, and more than 35,000 book titles, including a number of iconic reference works. Elsevier is part of RELX Group, a world-leading provider of information and analytics for professional and business customers across industries. http://www.elsevier.com

Media contact

Darren Sugrue
Elsevier
+31 20 485 3506
d.sugrue@elsevier.com

Elsevier

Related Magnetic Field Articles:

Magnetic field with the edge!
This study overturns a dominant six-decade old notion that the giant magnetic field in a high intensity laser produced plasma evolves from the nanometre scale.
Global magnetic field of the solar corona measured for the first time
An international team led by Professor Tian Hui from Peking University has recently measured the global magnetic field of the solar corona for the first time.
Magnetic field of a spiral galaxy
A new image from the VLA dramatically reveals the extended magnetic field of a spiral galaxy seen edge-on from Earth.
How does Earth sustain its magnetic field?
Life as we know it could not exist without Earth's magnetic field and its ability to deflect dangerous ionizing particles.
Scholes finds novel magnetic field effect in diamagnetic molecules
The Princeton University Department of Chemistry publishes research this week proving that an applied magnetic field will interact with the electronic structure of weakly magnetic, or diamagnetic, molecules to induce a magnetic-field effect that, to their knowledge, has never before been documented.
Origins of Earth's magnetic field remain a mystery
The existence of a magnetic field beyond 3.5 billion years ago is still up for debate.
New research provides evidence of strong early magnetic field around Earth
New research from the University of Rochester provides evidence that the magnetic field that first formed around Earth was even stronger than scientists previously believed.
Massive photons in an artificial magnetic field
An international research collaboration from Poland, the UK and Russia has created a two-dimensional system -- a thin optical cavity filled with liquid crystal -- in which they trapped photons.
Adhesive which debonds in magnetic field could reduce landfill waste
Researchers at the University of Sussex have developed a glue which can unstick when placed in a magnetic field, meaning products otherwise destined for landfill, could now be dismantled and recycled at the end of their life.
Earth's last magnetic field reversal took far longer than once thought
Every several hundred thousand years or so, Earth's magnetic field dramatically shifts and reverses its polarity.
More Magnetic Field News and Magnetic Field Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.