Mesoporous silica nanoparticles with fluorescent and magnetic dual-imaging properties to deliver fucoidan.

Fucoidan is a sulfated polysaccharide that is mainly extracted from brown algae. In this study, a simple and efficient method of hot water extraction, which is commonly used in industry, was used to obtain crude polysaccharides. Furthermore, agricultural waste was our source of biogenic silica, and it was then synthesized into drug carrier-nanoparticles. In combination with a popular drug delivery system, the carrier was doped with a dual imaging lanthanide metal and loaded with the drug. Fucoidan has decent bioactivities, such as anticancer activity. The extracted fucoidan is expensive, but we can exploit the nanocarrier to reduce the necessary dose of fucoidan. The experimental section is divided into three parts. The first part analyzed the chemical properties and antioxidant activity of the extracted fucoidan. The second part endowed the material with fluorescent and magnetic dual-imaging properties by incorporating Eu and Gd during the synthesis of rice husk mesoporous silica nanoparticles (rMSNs). The third part tested the anti-cancer ability of rMSN-EuGd@Fucoidan. The drug delivery system rMSN-EuGd@Fucoidan, which was synthesized in this research, showed cytotoxicity against A549 cancer cells. The results of the cell viability tests for fucoidan and rMSN-EuGd@Fucoidan were 58% and 47%, respectively. After inverse calculation from the TGA data yielded a value of 54.5%, we determined that the amount of fucoidan loaded in rMSN-EuGd@Fucoidan was 109 μg. Our results showed that rMSN-EuGd@Fucoidan needs less fucoidan to be effective, and its toxicity against A549 cells is higher than that of fucoidan.