Short interfering RNA molecules, or “siRNA” for short, have become an astounding prospect in the field of molecular genetics. Now, through the new delivery technique which encompasses gold nanoparticles, scientists have taken one big step towards realizing the dream that one day siRNA strands could be used to cure everything from HIV to cancer.
The interest that surrounds siRNA molecules is due to their ability to switch off their target genes. They do this by selectively interfering with messenger RNA molecules, which form the link between a gene and the ribosome which produces the protein it codes for. This means that siRNAs could theoretically act as specific drugs, possessing the ability to inactivate key genes from HIV and other viruses, or disable the human genes linked with conditions ranging from age-related sight loss to cancer.
The problem involved so far has been that siRNA strands get broken down too quickly once inside a cell. However, as always, science finds an answer. A team led by Chad Mirkin of Northwestern University in Evanston, Illinois, has used gold nanoparticles to play the role of an enzyme shield for siRNA strands.The delivery system consists of spheres of gold measuring just 13 nanometres in length, each able to carry about 30 short stretches of RNA bound to the gold using a connector molecule.
In experimentation, the new delivery system has proved successful in its absorption into human cells prepared in culture solutions. Also, the now protected siRNA showed a two-fold increase in its effectiveness as a gene deactivator.
The next steps involve testing within live organisms, as continued hope surrounds siRNA strands that they may one day serve as a cure for many terminal diseases present today.
Peter Aldhous, 25 February 2009, “Gold delivery could boost molecular medicine”, New Scientist, Retrieved March 25th 2009, from -http://www.newscientist.com.ezproxy.library.uq.edu.au/article/mg20126975.600-gold-delivery-could-boost-molecular-medicine.html
