In nanotechnology, a particle is defined as a small object that behaves as a whole unit with respect to its transport and properties. The
newly developed nanoparticles have a couple of unique properties. The particle is encased in a shell coated with a peptide that enables it to target tumor cells. Furthermore, the shell is etchable. This means that nanoparticles that do not hit their target can be broken down and eliminated.
The core of the nanoparticle employs a phenomenon called plasmonics. In plasmonics, nanostructured metals such as gold and silver resonate in light and concentrate the electromagnetic field near the surface. In this way, fluorescent dyes are enhanced, appearing about tenfold brighter than their natural state when no metal is present.
When the core is etched, the enhancement goes away and the particle becomes dim. This allows cancerous tumors to be located and visualised more clearly.
The nanoparticles also have other potential applications. Switching out the surface agent enables the targeting of different diseases through the use of different target receptors. Furthermore,
silver is an antibacterial agent and our targeting technology may make it possible to use silver nanoparticles in treating infections. It is thought that silver atoms bind to bacterial enzymes and subsequently cause the deactivation of enzymes, and thus the death of the bacterial cell.
The antimicrobial properties of silver have been known to cultures all around the world
for many centuries. The Phonecians stored water and other liquids in silver coated bottles to discourage contamination by microbes. Silver dollars used to be put into milk bottles to keep milk fresh, and water tanks of ships and airplanes that are "silvered" are able to render water potable for months. In 1884 it became a common practice to administer drops of aqueous silver nitrate to newborn's eyes to prevent the transmission of
Neisseria gonorrhoeae from infected mothers to children during childbirth. Despite the long history, new applications are being found today for silver technology.
The research was conducted at UC Santa Barbara. The research
findings appear in the journal
Nature Materials, in a paper titled “Etchable plasmonic nanoparticle probes to image and quantify cellular internalization.”
