Preparation and activity evaluation of zinc ion delivery system based on fucoidan-zinc complex

Zinc is a critical trace element in the human body, playing a key role in regulating various protein functions and cellular metabolism. Thus, maintaining zinc homeostasis is essential for human health, as zinc deficiency can directly contribute to the onset of numerous diseases. Effective supplementation with zinc ions offers a viable treatment for zinc deficiency. Polysaccharides, particularly natural polysaccharides, exhibit extensive physiological activities and serve as efficient systems for delivering zinc ions. Fucoidan (F) is an affordable, widely available polysaccharide with significant bioactivity and safety, attracting growing research interest. However, most studies focus on its physiological functions, while few explore the structure and effects of fucoidan-metal complexes. In this study, fucoidan (F) was chosen to complex with Zn2+ to form the fucoidan-zinc (F-Zn) complex, whose structure was characterized. The zinc ion content reached 9.15%, with zinc (II) predominantly complexed with sulfate groups in the F-Zn (II) complex. Evaluation demonstrated that the prepared fucoidan-zinc system, at a concentration of 110 μg/ml, exhibited no significant cytotoxicity toward HT22 cells. Furthermore, both F and F-Zn exhibited significant neuroprotective effects in an HT22 cell model induced by cisplatin. Additional investigations revealed that F and F-Zn could mitigate cisplatin-induced increases in reactive oxygen species levels and alleviate mitochondrial damage. The fucoidan-zinc complex presents itself as a promising zinc ion delivery system for treating zinc deficiency.