Self-crosslinked fucoidan nanoparticles via electron beam irradiation: Synthesis, physicochemical analysis, and drug delivery application

Naturally derived polysaccharides have great potential in biomedical applications due to their biocompatibility, biodegradability, and non-toxicity. In this study, we successfully synthesized nanoparticles of fucoidan, a sulfated polysaccharide derived from brown algae, via electron beam irradiation. This method enabled simple and efficient synthesis in aqueous solution without the need for chemical cross-linkers or toxic reagents. By adjusting the electron beam irradiation intensity and fucoidan concentration, the nanoparticle size could be tuned from 100 to 215 nm. Structural analysis (FT-IR, 1 H-NMR, XRD) confirmed that irradiation led to increased crystallinity and cross-linking. Additionally, rheological analysis suggested a mechanism by which electron beam irradiation induced simultaneous chain scission and cross-linking. Doxorubicin loading into the nanoparticles resulted in pH-sensitive drug release properties, demonstrating stability at physiological pH and accelerated release under acidic conditions. In cell and animal assays, the doxorubicin-loaded nanoparticles exhibited high cytotoxicity against EMT6 breast cancer cells and reduced tumor volume by more than four-fold in vivo. This study presents a green and scalable method for preparing fucoidan nanoparticles using electron beam irradiation; it demonstrates their potential applications in cancer therapy and drug delivery systems.