Doxorubicin loading fucoidan acetate nanoparticles for immune and chemotherapy in cancer treatment

► Doxorubicin loaded acetylated fucoidan (AcFu) nanoparticles were investigated for immunochemotherapy in cancer treatment. ► The nanoparticles exhibited first-order drug release behavior for 5 days. ► AcFu treated Raw264.7 macrophages overexpressed various anti-tumor cytokines. ► The nanoparticles resist to multidrug resistance characteristics of cancer cells. ► The nanoparticles have a promising potential for one-step immunochemotherapy. In order to develop immuno- and chemotherapy agents, self-organized acetylated fucoidan (AcFu) nanoparticles were designed. Doxorubicin (DOX), used as a model drug, was loaded into the AcFu nanoparticles by dialysis. The DOX loading efficacy and content were 71.1% and 3.6%, respectively. Approximately 140nm of spherical nanoparticles were obtained. DOX-loaded AcFu nanoparticles (DOX–AcFu) exhibited first-order drug release behavior for 5 days. Interestingly, AcFu treated Raw264.7 macrophages overexpressed various anti-tumor cytokines, such as tumor necrosis factor-alpha (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The ability of DOX–AcFu to suppress drug efflux was revealed by confocal microscope images and FACS analysis in multidrug resistance (MDR) cells. IC50 (50% inhibitory concentration) value of DOX–AcFu was lower than that of free DOX in the MDR model cells. Based on these results, we strongly suggest that AcFu nanoparticles have a promising potential for development as a one-step therapy containing agents for both immuno- and chemotherapy.