Development of transfection reagent using aminoclay nanoparticles for cancer therapy

Abstract

Various types of transfection agents using nanoparticles have been researched to develop a drug for gene therapy. Recently, organo-phyllosilicates and its modified materials, known for properties like high water solubility and cationic electricity, have emerged as bio-applicable materials. First, we have investigated the cytotoxic assay of Fe-aminoclay (FeAC) nanoparticles (NPs) and simultaneous imaging in cells by photoluminescent carbon nanodots (CD) conjugation. As increase of CD-FeAC NPs loading in HeLa cell in vitro, it showed slight cytotoxicity at $1,000 \mu g/mL$ but no cytotoxicity for normal cells upto concentration of $1,000 \mu g/mL$ confirmed by various cytotoxicity assays, possessing that CD-FeAC NPs can be used as potential drug delivery platforms in cancer cells with simultaneous imaging. Second, we developed FeAC NPs gene carrier which is capable of gene delivery. Negatively charged DNA can be strongly grafted onto the terminal region of FeAC NPs. By employing FITC conjugated FeAC NPs in HeLa cells, we successfully detected fluorescent signals using confocal bioimaging and fluorescence spectroscopy, which confirmed the optimal condition for cellular uptake. In addition, DNA was delivered by FeAC NPs to HeLa cells and successfully expressed fluorescent protein. Gene transfection efficiency was optimized to N/P ratio of 5. Lately, we developed fluorinated FeAC NPs for cancer therapy with low toxic effects. In this study, inhibitor gene of apoptosis in cancer cell was knocked out by siRNA gene delivery using fluorinated FeAC NPs. FITC modified siRNA is combined with fluorinated FeAC NPs to demonstrate cellular uptake. The FITC-siRNA was successfully detected by confocal bioimaging. Binding affinity between siRNA and fluorinated FeAC NPs was optimized using agarose gel electrophoresis. Target gene was successfully suppressed by the delivered siRNA, and confirmed by RT-PCR. Therefore, we can conclude that gene delivery using aminoclay NPs provides a new possibility of developing organo-phyllosilicates into an effective drug for cancer therapy.