In recent years, nanomaterials have been intensively studied and applied in various fields, including pharmaceutical applications. This platform can act as a carrier for anticancer drugs or for insoluble bioactive compounds. To increase the stability and prolong the effect of anticancer drugs, we have incorporated a sulfated polysaccharide fucoidan (Fu) into PAMAM dendrimer G3.0 to form a G3.0-Fu complex. Then, a nano-sized encapsulated anticancer drug, methotrexate (MTX), was successfully embedded in the synthesised dendrimer complex namely G3.0-Fu/MTX. Newly synthesised G3.0-Fu/MTX was characterised by transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurement.

Additionally, the loading efficiency of MTX was assessed via UV spectroscopy. Our findings revealed that upon combining with Fu, the G3.0 nanoparticle size increased from 4.3 ± 1.1 nm to 56 ± 6 nm. The changes in zeta potential aligned with drug entrapment efficiency and the results from TEM and DLS. The drug release activity of G3.0-Fu/MTX was increased compared to free MTX after 24 h. G3.0-Fu also showed high cytocompatibility in fibroblast cells. Taken together, the G3.0-Fu could be used to increase the encapsulation of several kinds of hydrophobic drugs and G3.0-Fu/MTX could be further studied in rheumatoid arthritis treatment.