Rice, Methodist researchers merge magnetic particles to detect, fight disease
Submicroscopic particles that contain even smaller particles of iron oxide could make magnetic resonance imaging (MRI) a far more powerful tool to detect and fight disease.
Silicon mesoporous particles, aka SiMPS, about 1,000 nanometers across contain thousands of much smaller particles of iron oxide. The SiMPs can be manipulated by magnets and gather at the site of tumors, where they can be heated to kill malignant tumors or trigger the release of drugs. The particles were created by an international team led by scientists at Rice University and The Methodist Hospital Research Institute in Houston.
Credit: Wilson Group/Rice University
Scientists at Rice University and The Methodist Hospital Research Institute (TMHRI) led an international team of researchers in creating composite particles that can be injected into patients and guided by magnetic fields. Once in position, the particles may be heated to kill malignant tissues or trigger the release of drugs at the site.
The "nanoconstructs" should fully degrade and leave the body within a few days, they reported.
The research appears online in the journal Advanced Functional Materials.
The team led by Rice chemist Lon Wilson and TMHRI scientist Paolo Decuzzi was searching for a way to overcome the challenges presented by iron oxide particles that are good at some things but not others, depending on their size.
Iron oxide particles have many excellent qualities: They can be manipulated with magnets, provide excellent contrast under MRI, create heat when triggered and degrade quickly. But they can't do all that at once. The team needed a way to decouple the functions from their sizes.
The answer was to package thousands of iron oxide particles – with magnetic cores as small as 5 nanometers across – inside larger particles.
The researchers made two such nanoconstructs, embedding iron oxide particles in silicon mesoporous particles (SiMPs) and discoidal polymeric nanoconstructs (DPNs). They knew from previous research that submicron-sized SiMPs and DPNs naturally accumulate within the tumor's blood vessels.
Iron oxide enhances the ability to position and hold the particles in place with magnets, said lead author and Rice graduate student Ayrat Gizzatov. "They get attracted by the magnet, and that induces another dipole-dipole magnetic interaction among the particles and increases their interparticle communication mechanism," he said.
Tests showed iron oxide particles made the nanoconstructs 10 times better than traditional contrast agents with what amounted to significantly lower doses of iron than used in current practice.
The new research also showed that, as a general principle, confining MRI contrast agents (like iron oxide) in geometric structures enhances their relaxivity – the property that makes the agents appear in MRI images. (The shorter the relaxation time, the greater the contrast in the image.)
While the particles are too big to target specific proteins, Gizzatov said it might also be possible to modify them with elements that will increase their accumulation in tumors.
Co-authors are Adem Guven of Rice; Jaehong Key, Santosh Aryal, Jeyarama Ananta, Xuewu Liu and Meng Zhong, all of TMHRI; Anna Lisa Palange and Daniele Di Mascolo of TMHRI and the University of Magna Graecia, Italy; Matteo Fasano and Antonio Cervadoro of TMHRI and the University of Turin, Italy; Cinzia Stigliano of TMHRI and the University of Bari, Italy; Eliodoro Chiavazzo and Pietro Asinari of the University of Turin; and Mauro Ferrari of Weill Cornell Medical College, New York.
The Cancer Prevention and Research Institute of Texas, the National Institutes of Health, the Welch Foundation, the Interpolytechnic Doctoral School of Turin, the Italian Ministry of Research, the Doctoral School of the University of Magna Graecia, the European Social Fund and the Regione Calabria supported the research.
Read the abstract at http://onlinelibrary.wiley.com/doi/10.1002/adfm.201400653/abstract
This news release can be found online at http://news.rice.edu/2014/06/16/nanoscale-composites-improve-mri/
Follow Rice News and Media Relations via Twitter @RiceUNews
Wilson Group: http://www.ruf.rice.edu/~ljwgroup/
Paolo Decuzzi bio: http://www.houstonmethodist.org/paolodecuzzi
Images for download:
Silicon mesoporous particles, aka SiMPS, about 1,000 nanometers across contain thousands of much smaller particles of iron oxide. The SiMPs can be manipulated by magnets and gather at the site of tumors, where they can be heated to kill malignant tumors or trigger the release of drugs. The particles were created by an international team led by scientists at Rice University and The Methodist Hospital Research Institute in Houston. (Credit: Wilson Group/Rice University)
Submicrometer particles that contain even smaller particles of iron oxide could make magnetic resonance imaging a far more powerful tool to detect and fight disease, according to researchers at Rice University. (Illustration by Ayrat Gizzatov/Rice University)
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is 6.3-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go here.
David Ruth | Eurek Alert!
Transporting spin: A graphene and boron nitride heterostructure creates large spin signals
16.08.2017 | Graphene Flagship
From hot to cold: How to move objects at the nanoscale
10.08.2017 | Scuola Internazionale Superiore di Studi Avanzati
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research