In this study, we propose doxorubicin (DOX) loaded oligonucleotides (ONTs) modified gold nanoparticles (AuNP) as a drug delivery system (DDS) for colorectal cancer therapy. DOX is one of representative anti-cancer drug and widely used by many research groups as a chemotherapy agent in the DDS. We utilized AuNPs as drug delivery vehicle, because of the advantages of AuNPs such as simple steps in synthesis, high surface-area-to-volume ratio, and biocompatibility. AuNPs were synthesized to be 13 nm diameter by conventional chemical reduction with citrate stabilizer. The G-C rich ONTs were used both for drug loading sites and AuNPs capping materials. The drug loading capacity of DOX loaded ONTs modified AuNPs (DOA) was represented by drug loading content (LC, w/w%), and drug entrapment efficiency (EE, %). The LC and EE of DOA was calculated as 3.02 and 81, respectively.
The SW480 cell line was obtained as targeting system of colorectal cancer therapy. The cytotoxicity effect on SW480 cells treated with DOA was performed at in vitro (MTT assay) and in vivo (tumor-bearing mouse). The cell viability of SW480 that treated with DOA for 24 hours, was 41.77 %. The tumor growth inhibition ratio was represented by treatment-control (T/C) ratio; the T/C ratio was found to be 0.69. Thus, our results suggest the use of DOAs as promising drug delivery systems for colorectal cancer therapy.