Salty nanoparticles slip into cancer cells to wreak destruction
Causing the death of cancer cells while leaving healthy ones intact is central to aims of researchers pursuing safer, more effective forms of treatment for the disease, and scientists have now come up with one that leans heavily on a common household item. The team’s new nanoparticles work as Trojan horses to sneak ions into cancer cells and cause their destruction, while also showing some exciting potential as a vaccine to guard against recurrence.
The technology was developed by researchers at the University of Georgia, whose newly developed cancer weapon is sodium chloride nanoparticles (SCNPs), also known as salt, which work by playing on cancer cells’ vulnerability to sodium ions. The membrane of a cell plays a vital gatekeeping role in maintaining a low sodium concentration inside the cell, and a much higher sodium concentration outside.
This balance is key to the well-being of the cancer cells, and so presents scientists with a great opportunity to intervene by shaking things up. The SCNPs are able to disguise the sodium ions they carry so that they go unrecognized by the membrane, and once they make their way inside, are able to unleash chaos in their new home.
Once inside the cancer cell, they dissolve into millions of sodium and chloride ions that wreak havoc on the cell's defense systems and eventually rupture the membrane. This not only induces cell death, but allows molecules to leak outside and trigger an immune response to further fight off pathogens.
“This mechanism is actually more toxic to cancer cells than normal cells, because cancer cells have relatively high sodium concentrations to start with,” says Jin Xie, associate professor of chemistry at the University of Georgia.
Injecting the SNCPs into tumors in mice suppressed the tumor growth by 66 percent compared to a control group, while bringing about no sign of side effects to major organs. They were also tested out as a vaccine, where the scientists delivered the SCNPs to mice with cancer cells that had already been killed off. The animals showed a “much greater resistance” to another cancer cell challenge, with all remaining tumor-free for over two weeks.
The vaccine potential of the SCNPs was tested further on tumor models, where a primary tumor was injected with SCNPs and secondary tumors were not. The secondary tumors then grew much more slowly, exhibiting a tumor inhibition rate of 53 percent.
Promisingly, the SCNPs simply turn into salt once they degrade, which means they are not harmful to the body. With further work, this technology could bring about more effective treatments with far fewer side effects for a range of cancers.
“This technology is well suited for localized destruction of cancer cells,” says Xie. “We expect it to find wide applications in treatment of bladder, prostate, liver, and head and neck cancer.”
The team has published its research in the journal Advanced Materials.
Source: University of Georgia