Magnetic graphene oxide nanoflakes for dual RNA interfering delivery and gene knockdown in prostate and liver cancers

The development of synthetic carriers for small interfering RNA (siRNA) and plasmids is crucial for effective gene therapy. In this study, we synthesized magnetic graphene oxide nanoflakes as carriers for siRNA delivery, with the goal of knockdown specific genes such as the green fluorescence protein (GFP). Our approach combined magnetically reduced graphene oxide with polyethylenimine (PEI) crosslinked to its surface using carbonyl diimidazole. To evaluate the adsorption capacity of the PEI-modified nanocomposite, we investigated its ability to bind two types of nucleic acids: short-hairpin (sh)RNA plasmids and siRNA targeting GFP. The nanocomposite exhibited significant adsorption, with maximum capacities of 426 ng/μg for shRNA and 71 ng/μg for siRNA, respectively. Simultaneous delivery of siRNA and shRNA using our designed nanocomposites was successfully achieved in human hepatoma and prostate cancer cells. Under magnetic guidance, the knockdown efficiencies reached 73.5 % in hepatoma cells for dual delivery of siRNA and shRNA. Our findings revealed that the nanocomplexes were internalized by the cells through a caveolae-dependent endocytosis mechanism. The demonstrated ability of the nanoflakes to efficiently transport siRNA and shRNA, with high loading capacity, controlled release, and magnetic targeting, resulted in effective GFP knockdown in vitro. These findings highlight the potential of magnetic graphene oxide nanoflakes as promising carriers for siRNA delivery and gene knockdown in therapeutic applications.