Study leader Teri W. Odom of Northwestern University said the research team also was able to directly image at nanoscale dimensions how nanoparticles interact with a cancer cell's nucleus.
"Our drug-loaded gold nanostars are tiny hitchhikers," Odom said in a statement. "They are attracted to a protein on the cancer cell's surface that conveniently shuttles the nanostars to the cell's nucleus. Then, on the nucleus' doorstep, the nanostars release the drug, which continues into the nucleus to do its work."
Odom and her team found their drug-loaded nanoparticles dramatically change the shape of the cancer cell nucleus -- what begins as a nice, smooth ellipsoid becomes an uneven shape with deep folds.
They also discovered that this change in shape after drug release was connected to cells dying and the cell population becoming less viable -- both positive outcomes when dealing with cancer cells, Odom said.
Since the initial research, the research team studied the effects of the drug-loaded gold nanostars on 12 other human cancer cell lines and the effect was much the same, Odom said.
"All cancer cells seem to respond similarly," Odom said. "This suggested that the shuttling capabilities of the nucleolin protein for functionalized nanoparticles could be a general strategy for nuclear-targeted drug delivery."
The findings were published in the journal ACS Nano.