Fucoidan with three functions extracted from Sargassum aquifolium integrated rice-husk synthesis dual-imaging mesoporous silica nanoparticle.

In this study, we used the nanoparticle delivery system to reduce the side effect of conventional cancer treatment- radiation therapy and chemotherapy. We used rice husk silicon source mesoporous silica nanoparticle doped in Eu and Gd as the carrier in the delivery system and to enable fluorescence and MRI dual-imaging functions for follow-up therapy. In addition, we choose a popular seaweed extract-fucoidan was extracted from the same brown algae-Sargassum aquifolium collected from Taiwan-Pingtung-Kenting-Chuanfan Rock. In this research, we used acid hydrolysis to prepared two different molecular weight fucoidan, the small molecular fucoidan (Fus) as drug, and the molecular weight approximately 1 kDa fucoidan (Ful) as the nanoparticle gatekeeper, and as targeting molecule for overexpressed P-selectin on the surface of the metastatic tumors. The results of the cell cytotoxicity experiment showed that HCT116 cancer cells have a survival rate of approximately 58.12% when treated with 200 μg/mL fucoidan. Dual-imaging rice husk mesoporous silica nanoparticles (rMSN-EuGd) were modified with 1 kDa fucoidan (Ful) as the gatekeeper and target, and the small molecule fucoidan (Fus) was loaded into nanoparticles (Ful-Fus@rMSN-EuGd) at a concentration of 200 μg/mL. The HCT116 cancer cells had a survival rate of approximately 55.56%. The cell cytotoxicity experiment results show that Ful-Fus@rMSN-EuGd can improve the anticancer effect of fucoidan, and the nanoparticle drug delivery system using fucoidan as a drug, target, and gatekeeper was successfully synthesized.