Multidrug release from nanoparticles in single cells

The release of two anticancer drugs from gold nanoparticles into a single leukaemia cell has been followed by surface-enhanced Raman scattering and dark force microscopy. Korean scientists at Soongsil University and Seoul National University attached imatinib and topotecan via self-assembly to the nanoparticles, followed by transferrin which was attached via a 4-carboxylic benzenethiol linker.

When the modified nanoparticles were loaded into single K562 cells, it took one hour for the conjugates to enter the cells as described in the Journal of Raman Spectroscopy. The drugs tended to remain attached to the nanoparticles until the addition of glutathione, which released them into the cells. However, slow release was also prompted by intracellular glutathione, which suggests that bound drugs can be released from gold nanoparticles by natural intracellular content, providing a process for targeted drug delivery.