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Researchers at UC Santa Barbara have developed a nanoparticle that equips two unique and important features. The nanoparticles are spherical in shape and silver in composition, encased in a shell that is coated with a peptide that enables it to target tumor cells. 

Further, the shell is etchable so when nanoparticles don't hit their target, those can be broken down and eliminated easily.

The newly devised nanoparticle employs a phenomenon called plasmonics. In plasmonics, nano-structured metals i.e. gold and silver, resonate in light and concentrate the electromagnetic field near the surface. In similar fashion, fluorescent dyes are enhanced appearing about tenfold brighter than their natural state when none of the metals are present. 

Eventually, when the core is etched, the enhancement goes away making the particle dim. 

"The disassembly is an interesting concept for creating drugs that respond to a certain stimulus," said Gary Braun, a postdoctoral associate in the Ruoslahti Lab in the Department of Molecular, Cellular and Developmental Biology (MCDB) and at Sanford-Burnham Medical Research Institute, in the press release. "It also minimizes the off-target toxicity by breaking down the excess nanoparticles so they can then be cleared through the kidneys."

Researchers added that the method for removing nanoparticles unable to penetrate target cells is unique. 

"By focusing on the nanoparticles that actually got into cells," Braun added, "we can then understand which cells were targeted and study the tissue transport pathways in more detail."

"These new nanoparticles have some remarkable properties that have already proven useful as a tool in our work that relates to targeted drug delivery into tumors," said Erkki Ruoslahti, adjunct distinguished professor in UCSB's Center for Nanomedicine and MCDB department and at Sanford-Burnham Medical Research Institute, in the press release. 

"They also have potential applications in combating infections. Dangerous infections caused by bacteria that are resistant to all antibiotics are getting more common, and new approaches to deal with this problem are desperately needed. Silver is a locally used antibacterial agent and our targeting technology may make it possible to use silver nanoparticles in treating infections anywhere in the body."

The research has been published in the journal Nature Materials.