Nanoprobe for blood cancer
doi:10.1038/nindia.2011.109 Published online 22 July 2011
New research has shown that a modified fluorescent nanocluster (NC) of gold atoms could be used to detect acute myeloid leukaemia (AML), a type of blood cancer that affects bone marrow.
Traditionally, flow cytometry is used to diagnose disorders such as blood cancers. However, the fluorescent molecules used in this technique can be destroyed by prolonged light exposure. Also, the cells are fluorescent only at visible wavelengths.
To bypass this limitation, the researchers produced gold nanoclusters (NCs) with 25–28 atoms in each cluster. They covered the NCs with a protein and attached antibodies to the surface. These antibodies were specific to the antigen CD33, which sits on the cell membrane of AML cells, giving rise to the nanoconjugate Au-NC-CD33.
Leukaemia cells demonstrated enhanced uptake at Au-NC-CD33 concentrations of 4.5 μg ml–1 and 9 μg ml–1, whereas the peripheral blood cells did not. In addition, the leukaemia cells showed a greater uptake of Au-NC-CD33 than unconjugated Au-NC. When irradiated with ultraviolet and visible light, leukaemia cells with the nanoconjugates fluoresced at red and near-infrared wavelengths.
"These fluorescent gold NCs may help in the non-invasive detection of leukaemia and stem cell disorders and the selective delivery of drugs to leukaemia cells," says lead researcher Manzoor Koyakutty.