The PA-receptor mediated internalization of carboplatin loaded poly-anionic DNA-nanowires for effective treatment of resistant hepatic-cancer HepG-2 cells

DNA-nanowire (DNA-NW) shaped stiff nano-structures were synthesized using circular DNA-nanotechnology resulting from the polymerization of DNA-triangles. Topologically sturdier DNA triangular-tiles were formulated utilizing circular-templates (84-nt) by self-assembling with various staple-strands. The long micrometer-sized nano-ribbon lattices resulting from the polymerization of the triangular-tiles underwent self-coiling phenomenon due to the double-helix curvatures in the DNA-nanostructures. This self-coiling caused morphological transition in the resulting nano-lattice from the nano-sheet structure to the more-compact and dense DNA-NW. AFM and confocal-imaging suggested successful execution of the designed morphology of the DNA-NW (3-4 mu m long & <= 30 nm wide). The decreased electrophoretic mobility during the PAGE-analysis also confirmed the polymerization of the nanometer-sized DNA-triangles into micrometer-sized long DNA-NW structures. Carboplatin (CRPT) loading onto DNA-NW was confirmed from the characterizations of UV-vis absorbance spectroscopy and confocal fluorescence microscopy. The biocompatibility of various concentrations of the DNA-NWs (blank) was confirmed from the MTT and flow-cytometry analysis. CRPT loaded DNA-NW showed sustained (time-dependent) cytotoxicity to the HepG-2 cells rich in poly-anionic (PA) receptors than the control cell-line (CHSE-214 cell-line) from the salamander-embryo lacking poly-anionic receptors. Confocal imaging results further confirmed the PA-receptors mediated cell-surface binding of the DNA-NW and time-dependent cell-internalization.