Mar 5 2009
Scientists of the national German metrology institute, the Physikalisch-Technische Bundesanstalt (PTB), have developed a highly sensitive measuring method with which the efficiency of gene transfer in cases if cardiovascular diseases can be investigated. The researchers determine, accurate to the picogram per cell, the quantity of magnetic particles that are situated on the gene – and thus also the quantity of the therapeutically effective genes or cells. In a joint study with the University of Bonn it became clear: By means of the magnetic method it is possible to dramatically increase the efficiency of the gene transfer in comparison to the non-magnetic method.
Magnetic nanoparticles can support or even enable gene transfer under clinically relevant experimental conditions. For the transduction of human cells, gene carriers were coupled to magnetic nanoparticles and dragged into the cells by magnetic field gradients. The efficiency of magnetic transduction turned out to be much higher than the nonmagnetic procedure. An additional welcome side effect is the "magnetization" of the cells after the incorporation of nanoparticles. This may enable the targeted transport of the cells to regions of interest.
A closer look at the underlying mechanism of magnetic gene transfer was taken by the quantification of the magnetic material that was delivered to the cells. The required highly sensitive measurements in the range of a few picogramm per cell were made by PTB using magnetorelaxometry. The good correlation between measurement data and gene transfer encourages to use magnetorelaxometry for monitoring the efficiency of gene and cell transfer, possibly even in vivo.