Study shows salt nanoparticles are toxic to cancer cells

A new study at the University of Georgia reports that researchers have found a way to attack cancer cells that may be less harmful to the patient. Sodium chloride nanoparticles –better known as salt– are toxic to cancer cells and offer the potential to develop therapies that have fewer negative side effects than current treatments.

Salt as a Trojan Horse

Led by Jin Xie, junior professor of chemistry, the study found that SCNPs can be used as a Trojan horse to deliver ions into diseased cells and destroy them from the inside. SCNPs turn into salt when they break down, so they are not harmful to the body.

“This technology is well suited for local destruction of cancer cells,” Xie said. “We expect it to have widespread use in the treatment of bladder, prostate, liver and head and neck cancers.”

“This mechanism is more toxic to cancer cells than to normal cells because cancer cells initially have relatively high sodium concentrations,” Xie said.

In the mouse experiment, Xie and the team tested SCNPs as a potential cancer therapeutic and injected SCNPs into tumors. They found that SCNP treatment suppressed tumor growth by 66 percent compared to the control group. There was no evidence of weight loss or major organ toxicity.

A vaccine against cancer?

They also conducted a vaccination study in which mice were vaccinated with cancer cells that had first been killed with SCNPs or by freezing and thawing. These mice showed much greater resistance to subsequent infection with live cancer cells, with all animals remaining tumor-free for more than two weeks.

The researchers also examined cancer immunity in a tumor model. After injecting SCNPs into primary tumors and untreated secondary tumors, they found that the secondary tumors grew at a much slower rate than the control and had a tumor inhibition rate of 53 percent.

Taken together, the results suggest that SCNPs killed cancer cells and converted the dying cancer cells into an in situ vaccine.

SCNPs are unique in the world of inorganic particles because they are made of a benign material and their toxicity is based on the nanoparticle shape, according to Xie.

“With a relatively short half-life in aqueous solutions, SCNPs are more suitable for local rather than systemic therapy. The treatment results in immediate and immunogenic death of cancer cells,” he said. “After treatment, the nanoparticles are reduced to salts that are fused with the body’s fluid system and do not cause systematic or accumulative toxicity. No signs of systematic toxicity were observed with SCNPs injected at high doses.”

The study was carried out inAdvanced Materials published.