Brown Chemists Create Cancer-Detecting NanoparticlesMay 28, 2008A team led by a Brown University chemist has created the smallest iron oxide nanoparticles to date for cancer detection by magnetic resonance imaging (MRI). The magnetic nanoparticles operate like tiny guided missiles, seeking and attaching themselves to malignant tumor cells. Once they bind, the particles emit stronger signals that MRI scans can detect. Magnetic resonance imaging (MRI) can be a doctor's best friend for detecting a tumor in the body without resorting to surgery. MRI scans use pulses of magnetic waves and gauge the return signals to identify different types of tissue in the body, distinguishing bone from muscle, fluids from solids, and so on. Scientists have found that magnetic nanoparticles can be especially helpful in locating cancerous cell clusters during MRI scans. Like teeny guide missiles, the nanoparticles seek out tumor cells and attach themselves to them. Once the nanoparticles bind themselves to these cancer cells, the particles operate like radio transmitters, greatly aiding the MRI's detection capability.
Now, Brown University chemist Shouheng Sun and a team of researchers have created the smallest magnetic nanoparticles to date that can be employed on such seek-and-find missions. With a thinner coating, the particles also emit a stronger signal for the MRI to detect. The results have been published online this week in the Journal of the American Chemical Society. Brown graduates students Jin Xie, Chenjie Xu and Sheng Peng collaborated on the research, along with Professor Xiaoyuan Chen and his associates from Stanford University. The team created peptide-coated iron oxide nanoparticles - particles billionths of a meter in size. The researchers injected the particles into mice and tested their ability to locate a brain tumor cell called U87MG. Sun and his collaborators concentrated specifically on the nanoparticle's size and the thickness of the peptide coating, which ensures the nanoparticle attaches to the tumor cell. Size is important because the trick is to create a nanoparticle that is small enough to navigate through the bloodstream and reach the diseased area. Bigger particles tend to stack up, creating the circulatory system's version of a traffic jam. Sun's team developed a nanoparticle that is about 8.4 nanometers in overall diameter - some six times smaller than the size of particles currently used in medicine. "We wanted to make (the nanoparticle) very small, so the body's immune system won't recognize it," Sun explained. "That way, you let more particles interact with and attach to the tumor cell." Nanoparticles are important in MRI detection because they enhance what scientists refer to as the "contrast" between the background, such as water molecules in the body, and a solid mass, such as a tumor. The coating, while integral to the nanoparticles' attachment to the tumor cell, also is crucial to establishing the "signal-to-noise" ratio that a MRI uses. The thinner the coating, the stronger the emitted signal and vice versa. Sun's team outfitted their nanoparticles with a two-nanometer thick peptide coating - 10 times thinner than the coating available in popular MRI contrast agents such as Feridex. Sun's nanoparticles are like having a 50,000-watt radio transmitter versus a 150-watt station; it's easier for the MRI to "hear" the stronger signal and to hone in on the signal's source. Another important feature of the team's work is discovering that the RGD peptide coating binds almost seamlessly to the U87MG tumor cell. The team plans to test the particle's ability to bind with other tumor cells in further animal experiments. The National Cancer Institute, part of the National Institutes of Health, and the Department of Energy's Experimental Program to Stimulate Competitive Research (EPSCoR) funded the research. Brown University Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Lymph Nodes Synthetic Biology Stardust Infectious Diseases Cancer Survival Cancer Detection Perception Myosin Brown Dwarf Cortisol Head Neck Cancer Mental Disorder Cognitive Decline Bullying Hygiene Ice Core Stereotypes Brain Tumors Food Safety Galaxy Sexual Selection Amyloid-beta Planets Biodiversity Amino Acids
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Related Nanoparticles Current Events and Nanoparticles News Articles University of Leicester researchers discover new fluorescent silicon nanoparticles Researchers in the Department of Physics and Astronomy at the University of Leicester have developed a new synthesis method, which has led them to the discovery of fluorescent silicon nanoparticles and may ultimately help track the uptake of drugs by the body's cells. Making nanoparticles in artificial cells Two new construction manuals are now available for the world's smallest lamps. Based on these protocols, scientists from the Max Planck Institute of Colloids and Interfaces have tailor-made nanoparticles that can be used as position lights on cell proteins and, possibly in the future as well, as light sources for display screens or for optical information technology. Singapore nanotechnology combats fatal brain infections Doctors may get a new arsenal for meningitis treatment and the war on drug-resistant bacteria and fungal infections with novel peptide nanoparticles developed by scientists at the Institute of Bioengineering and Nanotechnology (IBN) of Singapore and reported in Nature Nanotechnology. New nanoparticles could revolutionize therapeutic drug discovery A revolutionary new protein stabilisation technique has been developed by scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) which could lead to 30 per cent more proteins being available as potential targets for drug development - opening up exciting possibilities in drug discovery. Implant bacteria, beware: Researchers create nano-sized assassins Staphylococcus epidermidis is quite an opportunist. Commonly found on human skin, the bacteria pose little danger. But S. epidermidis is a leading cause of infections in hospitals. Research explores interactions between nanomaterials, biological systems The recent explosion in the development of nanomaterials with enhanced performance characteristics for use in commercial and medical applications has increased the likelihood of people coming into direct contact with these materials. NIST researchers 'all aglow' over new test of toxin strength A new National Institute of Standards and Technology (NIST) assay using a "glow or no glow" technique may soon help the U.S. Department of Homeland Security (DHS) defend the nation against a spectrum of biological weapons that could be used in a terrorist attack. Shape matters in the case of cobalt nanoparticles Shape is turning out to be a particularly important feature of some commercially important nanoparticles-but in subtle ways. UCF researcher's nanoparticles could someday lead to end of chemotherapy Nanoparticles specially engineered by University of Central Florida Assistant Professor J. Manuel Perez and his colleagues could someday target and destroy tumors, sparing patients from toxic, whole-body chemotherapies. Nanocrystals Reveal Activity Within Cells Researchers at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory have created bright, stable and bio-friendly nanocrystals that act as individual investigators of activity within a cell. More Nanoparticles Current Events and Nanoparticles News Articles |
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