Scientists at Northwestern University have developed gold nanostars for effective delivery of drugs into a cancer cell's nucleus. The study was performed on human ovarian and cervical cancer cells.
Teri W. Odom
The gold nanostars were loaded with the drug AS1411, a single-stranded DNA aptamer. This drug has the capability to bind to the protein nucleolin, which is over-expressed in cancer cells. It uses nucleolin as a shuttle and hitchhikes on them into the cell nucleus. The scientists then used ultrafast pulses of light to cleave the bond attachments that had taken place between the thiolated DNA aptamers and the gold nanostar surface. The aptamers can now enter the cancer cell’s nucleus.
The star-shaped gold nanoparticle measures approximately 25 nm wide and has around five to 10 points. A biocompatible synthesis was used for making the nanostars. They had a large surface area that allowed more drug molecules to be loaded. The researchers found that the gold nanostars were able to release the drugs easily and that their star shape allowed concentration at specific points.
This drug-delivery method could be useful for treating certain breast and skin cancers, where the tumors were close to the skin’s surface.
The researchers led by Teri W. Odom, also directly imaged the interaction between the nanoparticles and the cancer cell's nucleus at nanoscale dimensions. They used electron microscopy and discovered that the drug-loaded nanoparticles changed the shape of the nucleus. They became an uneven shape with folds. This was associated with the death of cells and the decrease in viability of the cell population. These two factors are an advantage when treating cancer cells.
Odom is a professor of materials science and engineering in the McCormick School of Engineering and Applied Science and the Board of Lady Managers of the Columbian Exposition Professor of Chemistry in the Weinberg College of Arts and Sciences.
The results of this study have been published in ACS Nano.