Synthesis of Polynucleotide Modified Gold Nanoparticles as a High Potent Anti-cancer Drug Carrier

Gold nanoparticles have been developed for the photoacoustic imaging, delivery of genes and laser induced photothermal therapy. In this study, we have developed oligonucleotide conjugated gold nanoparticles as the carrier for simultaneous DNA and anti-cancer nucleoside delivery. The polynucleotide-nanoparticle complex presented higher capacity in carrying 5-FU anti-cancer compounds than the original gold particles. The hydrodynamic size of the gold nanoparticles increased from 25 to 35 nm with an increase in the negative surface charge from -9.58 to 21.66 mV after polynucleotide conjugation and drug loading. A positive association between environmental pH and drug release was observed in PBS, which implied their potential use in the controlled localized drug release in the lower GI tract. The MTT assay revealed dose dependent cytotoxicity to colon cancer cell line than free compounds. These results suggest the potential use of this new polynucleotide-gold nanoparticles complex as the environmental controlled anti-cancer nanocapsule, especially suitable for per oral colon cancer chemotherapy.