Ethylenediamine functionalized-single-walled nanotube (f-SWNT)-assisted in vitro delivery of the oncogene suppressor p53 gene to breast cancer MCF-7 cells

Abstract

A gene delivery concept based on ethylenediamine-functionalized single-walled carbon nanotubes (f-SWCNTs) using the oncogene suppressor p53 gene as a model gene was successfully tested in vitro in MCF-7 breast cancer cells. The f-SWCNTs-p53 complexes were introduced into the cell medium at a concentration of 20 μg mL⁻¹ and cells were exposed for 24, 48, and 72 hours. Standard ethidium bromide and acridine orange assays were used to detect apoptotic cells and indicated that a significantly larger percentage of the cells (approx 40%) were dead after 72 hours of exposure to f-SWCNTs-p53 as compared to the control cells, which were exposed to only p53 or f-SWCNTs, respectively. To further support the uptake and expression of the genes within the cells, green fluorescent protein-tagged p53, attached to the f-SWCNTs was added to the medium and the complex was observed to be strongly expressed in the cells. Moreover, caspase 3 activity was found to be highly enhanced in cells incubated with the f-SWCNTs-p53 complex, indicating strongly induced apoptosis. This system could be the foundation for novel gene delivery platforms based on the unique structural and morphological properties of multi-functional nanomaterials.

Keywords:

• carbon nanotubes
• gene delivery
• cancer cells
• p53 oncogene suppressor

Acknowledgements

Financial support from the Arkansas Science and Technology Authority (ASTA) grant nr 08-CAT-03, the US Army Telemedicine, and Advanced Technology Research Center is highly appreciated. AR-P was supported by the NIH-GM075893 grant.

Disclosure

The authors declare no conflicts of interests in this work.