[bottombutton]

They genetically engineered a kind of bacteria that divides into non-living 'nanocells' that can't multiply further. These cells contain a special kind of RNA and a cell entry mechanism that lets them enter the cancer cells. The RNA interrupts the cell's ability to prepare for division. The article kind of implied that these nanocells follow the bloodstream pathways that cancer cells open when they metastasize.

The researchers main concern was whether those nanoncells would also enter healthy cells, but the tests seem to show healthy cells were not affected.