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

Alokita Karmakar², Stacie M Bratton¹, Enkeleda Dervishi², Anindya Ghosh³, Meena Mahmood², Yang Xu², Lamya Mohammed Saeed², Thikra Mustafa², Dan Casciano², Anna Radominska-Pandya¹, Alexandru S Biris^2
1Biochemistry Department, University of Arkansas for Medical Sciences; ²Nanotechnology Center, Applied Science Department; ³Department of Chemistry, University of Arkansas, Little Rock, AR, USA

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