As they report in the journal Angewandte Chemie, their work involves magnetic iron oxide particles with a fluorescence dye, RNA fragments, and a special peptide attached.
The peptide is present to specifically identify the cancer cells; the RNA fragments suppress the special cancer-cell genes, killing the cells. The magnetic particles act as a contrast agent for magnetic resonance imaging, and the fluorescence dye allows for microscopic imaging of the target cells.
In order to build a protein according to the genetic information in a cell, the gene on the DNA is read off and translated into a “stencil”, mRNA, which is then used by the cell as a blueprint for the protein. The mRNA is a good point of attack to stop the synthesis of proteins required for tumor growth. To achieve this, siRNAs (small interfering RNAs) are introduced into the cell. These are short, double-stranded RNA fragments that bind specifically to the target mRNA. Inside the cell, a special protein complex binds to the siRNA, which unwinds and cleaves the mRNA. In this unprotected form, the mRNA is rapidly degraded by the cell.
When bound to nanoparticles, the siRNAs are easier to slip into cells. In order to specifically target cancer cells, the particles carry a short peptide, called RGD, which points the way: RGD strongly binds to an integrin, a membrane protein that is anchored to metastasizing tumor cells in much higher amounts than in healthy tissue. The integrins with RGD-equipped nanoparticles are actively brought into the cell interior with their cargo intact (receptor-mediated endocytosis).
The magnetic particles not only act as an aide for transport, they are also a contrast agent for MRI. This reveals where the tumors are, whether the particles are concentrating there, and how the treatment is progressing. If higher resolution is required, the fluorescence dye molecules come into play. In histological slides of tissue samples, they make it possible to see how the magnetic particles are taken up by individual cells an in which cell compartments they are concentrated.
Author: Jinwoo Cheon, Yonsei University, Seoul (South Korea), http://chem.yonsei.ac.kr/~cheon/
Title: All-in-One Target-Cell-Specific Magnetic Nanoparticles for Simultaneous Molecular Imaging and siRNA Delivery
Angewandte Chemie International Edition, doi: 10.1002/anie.200805998
Further reports about: > Angewandte Chemie > Cancer > Direct Methanol Fuel Cells > RGD > RNA > RNA fragments > cancer cells > cancer-cell genes > contrast agent > disable tumor cells > fluorescence dye > mRNA > macroscopically > magnetic iron oxide particles > magnetic particles > metastasizing tumor cells > microscopically > small interfering RNA > special peptide > suppression
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research