Suicide gene on quantum dots
doi:10.1038/nindia.2010.151 Published online 29 October 2010
New research has shown that polymer-modified quantum dots could be used to ferry a suicide gene. The delivery of such a gene could cause the mass death of cancer cells, and could therefore be useful in the development of anticancer therapy.
In addition to the development of new, biocompatible gene-delivery vehicles, monitoring the transport and sustained release of therapeutic genes is essential for gene therapy. To achieve these goals, the researchers used quantum dots (QDs).
Cadmium-based quantum dots are toxic to biological systems. The researchers therefore produced manganese-doped zinc sulphide quantum dots as a safer alternative. They coated the quantum dots with chitosan, a naturally occurring biopolymer, to make them soluble and biocompatible.
The researchers first studied the DNA binding efficacy of these chitosan-modified QDs by testing how they bind to the cytosine deaminase-uracil phosphoribosyl transferase gene. This gene converts prodrug 5-fluorocytosine to 5-fluorouracil and other toxic metabolites for anticancer therapy.
In studies with human colonic adenocarcinoma cells, the researchers found that 90% of the cells were viable, thus proving that the chitosan-modified QDs are biocompatible. The results of this study indicate the possibility of using these composites as a 'self-tracking' gene delivery system in suicide gene therapy, say the researchers.
- Sanpui, P. et al. Incorporation of gene therapy vector in chitosan stabilized Mn2+-doped ZnS quantum dot. Mater. Lett. 64, 2534-2537 (2010) | Article