UCSB Researchers Target Tumors Using Silver Nanoparticles

Researchers at the University of California Santa Barbara (UCSB) have developed a new platform that increases the efficiency of drug delivery and which enables excess particles to be washed away. The platform uses a nanoparticle that is spherical in shape and composed of silver. The nanoparticle is also encased in a shell that is coated with a peptide that allows it to find and target tumor cells. The shell is also etchable, meaning that nanoparticles that don’t find tumor cells can be broken down easily and eliminated from the body.

The researchers’ nanoparticles use plasmonics, where metals concentrate the electromagnetic field near the surface, making fluorescent dyes appear to be 10 times brighter than their natural state. When the core of a nanoparticle is etched, the enhancement property is reduced and the particle becomes dim. The nanoparticle’s etching technique uses biocompatible chemicals, which ensures that silver nanoparticles outside living cells can be broken down. The intact nanoparticles remain, which allow researchers to determine which cancer cells were targeted and how much of a drug was delivered to a particular cell.

Gary Braun, a postdoctoral associate at the Ruoslahti Lab in the Department of Molecular, Cellular and Development Biology that worked on the research, talked about the disassembly process. “The disassembly is an interesting concept for creating drugs that respond to a certain stimulus,” he said. “It also minimizes the off-target toxicity by breaking down the excess nanoparticles so they can then be cleared through the kidneys. By focusing on the nanoparticles that actually got into cells we can then understand which cells were targeted and study the tissue transport pathways in more detail.”

The researchers’ findings were published in the journal Nature Materials.