Estradiol functionalized multi-walled carbon nanotubes as renovated strategy for efficient gene delivery†
The present work focuses on the development and characterization of the estradiol functionalized CNTs for efficient gene delivery applications. Simple carbidoiimide chemistry was employed to synthesize Es-PEG-CNTs and the resulting conjugate was authenticated by various spectrometric and chromatographic techniques. The nanoplexes of the resulting conjugate were carefully optimized for maximum encapsulation of pDNA (for induction of GFP). The successful encapsulation of the pDNA within nanoplexes was assessed using agarose gel electrophoresis and DNase protection assay. Exhaustive cell culture experiments have been conducted to evaluate the potential of nanoplexes in inducing the GFP expression in estrogen positive and estrogen negative cell lines. The results revealed 19.33-fold and 3.29-fold higher in vitro transfection in estrogen positive MCF-7 cells as compared to that of plain pDNA and Lipofectamine®, respectively. The remarkably higher transfection could be attributed to the intracellular localization of the surface functionalized nanoplexes in the vicinity of nucleus with Pearson's coefficient >0.9. Interestingly, >80% cell viability was noted for Es-PEG-CNTs in contrast to that of non-functionalized CNTs and lipofectamine which were found to be relatively toxic at tested concentrations. The potential of the developed nanocarrier was also challenged by intratumoral injection in animals and similar results were also noted in in vivo experiments. To conclude, the developed nanoplexes pose great potential in delivering the pDNA for difficult to treat diseases such as cancer.