Dec 8, 2010
Aptamer conjugated magnetic particles perform surgical actions
Aptamers have been attached to magnetic nanoparticles that recognize only selected cancer cells. Dubbed nanosurgeons, these modified nanoparticles can be controlled externally by a three-dimensional magnetic field to perform surgical actions.
Developed by researchers from the Bio Nano Electronics Research Center at Toyo Univeristy, Japan, the particle-based system could one day provide an alternative to complicated invasive surgery for the treatment of cancer or any other similar kinds of disease. In addition, the nanosurgeons may be able to target remote areas where any surgery is difficult with the benefit of minimal or possibly no collateral damage.
To create the nanosurgeons, the group selected the single-stranded DNA aptamer, GB-10, which is specific for Tenacin-C receptors on glioma cells. These aptamers were conjugated to carboxylated dextran coated super paramagnetic nanoparticles (250 nm in size) to introduce the specificity to the particle-based system. The specificity of aptamer conjugated magnetic nanoparticles towards cancer cells is much higher compared with normal cells.
Nanosurgeons could perform surgical actions such as dissecting, pulling and moving (removing) once attached to target cells thanks to the application of externally applied three-dimensional rotational magnetic fields (see diagram).
In the study, the frequency and intensity of the magnetic field were varied between 1 and 5 Hz and 9.55 kA/m, which correspond to a magnetic flux density of 12 mT. The frequency was varied between 1 and 5 Hz to identify the optimum operating condition for performing surgical actions.
In vitro studies and cell-based assays have shown that cell viability and proliferation was completely absent in the removed cells. By changing the target specific ligand (aptamers), nanosurgeons could be customized for any target cell.
The current work also demonstrates the capability of nanosurgeons to induce cell death and shows that the particles become more effective in their surgical actions and at inducing cell death when in a low frequency rotational magnetic field.
Looking ahead, the researchers are interested in addressing the proper rendering of nanosurgeons in clinical trials for non-invasive surgical methods.
More information can be found in the journal Nanotechnology.
About the author
Prof. D Sakthi Kumar works at the Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Japan. His current research interest is focused on exploring the possibilities of developing nanosurgeons which perform surgical actions remotely. In parallel, he is also working in the fields of nanodrug delivery, biomaterials, bio/chemical sensors and quantum dots for imaging as well as solar-energy conversion. Prof. Toru Maekawa, who is working at the same centre, is interested in delveloping novel methods to magnetize nanostructural materials and to develop nanomaterials under critical temperatures.