Scientists at UC Santa Barbara have designed a silver spherical nanoparticle encased in a shell coated with a peptide that enables it to target tumor cells. The shell is etchable so those nanoparticles that don’t hit their target can be broken down and eliminated. The research findings appear in the journal Nature Materials.
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 (to identify tumor cells) 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.
UCSB’s Ruoslahti Research Laboratory also developed a simple etching technique using biocompatible chemicals to rapidly disassemble and remove the silver nanoparticles outside living cells. This method leaves only the intact nanoparticles for imaging or quantification, thus revealing which cells have been targeted and how much each cell internalized.