Preparation and anti-tumor activities on A549 cell line of Fucoidan-Stabilized gold nanoparticles

Abstract

Gold nanoparticles (AuNPs) are attractive to be employed in various applications. Synthesis of AuNPs using the natural substances renders benefits due to avoidance of chemical utilization. This study successfully synthesized AuNPs using natural fucoidan, Takara Kombu fucoidan (TK fucoidan) and Okinawa Mozuku fucoidan (OM fucoidan) obtained from marine brown algae. The optimum weight ratios of gold (Au) to fucoidan for preparation of AuNPs by OM fucoidan (OM-AuNPs) and TK fucoidan (TK-AuNPs) were 1:20 and 1:50, respectively. The average sizes of the obtained AuNPs were 8.54 ± 2.96 nm and 10.74 ± 4.78 nm and zeta potentials of the AuNPs were -37.77 ± 4.83 and -21.72 ± 1.31 mV, for OM-AuNPs and TK-AuNPs, respectively. According to the results, OM-AuNPs were mono-dispersed and more stable than TK-AuNPs. Hence, the difference in fucoidan type might affect the formation of AuNPs. In addition, the fucoidan-stabilized AuNPs were investigated on anti-tumor activities on A549 lung cancer cell line. The results revealed that OM-AuNPs and TK-AuNPs had a toxic effect toward cancer cells greater than the corresponding fucoidans in an anchorage-dependent condition and no sign of resistance to OM-AuNPs and TK-AuNPs was observed in an anchorage-independent condition. Likewise, OM-AuNPs containing 300 µg/ml had a slight inhibitory effect (~16% inhibition) on A549 cell invasion which might be due to an anti-adhesive effect on the cancer cells to fibronectin (~30% inhibition) and suppression of MMP-2 production of A549 cells (~60% inhibition). Conclusively, AuNPs stabilized by algal fucoidans might be promising agents for cancer treatment which should be further investigated on anti-tumor mechanisms of the AuNPs and in vivo study.