Preparation and characterization of selenium nanoparticles decorated by Spirulina platensis polysaccharide

Selenium nanoparticles (SeNPs) have attracted lots of attention recently owing to their excellent bioavailability and low toxicity. However, the stability of SeNPs needs to be improved. To enhance the stability of SeNPs, we used Spirulina platensis polysaccharides (SPs) as stabilizers to prepare SPs-SeNPs. The SPs-SeNPs were spherical, with a mean particle size of 73.42 ± 0.69 nm. The optimal preparation conditions for the SPs-SeNPs were a SPs concentration of 100 mg/L, ascorbic acid/sodium selenite concentration ratio of 3:1 and reaction time of 6 hr. The prepared SPs-SeNPs were stable for 75 d at 4°C. Furthermore, MTT assay showed that the median toxic concentration (TC₅₀ ) of SPs-SeNPs was approximately 22,000 μg/L. In contrast, the TC₅₀ value of selenite was approximately 400 μg/L, which confirmed that the cytotoxicity of SPs-SeNPs on RAW264.7 cells was significantly reduced compared with sodium selenite. In conclusion, SPs can improve the stability of SeNPs. The toxicity of SPs-SeNPs is lower than that of sodium selenite. PRACTICAL APPLICATIONS: Spirulina platensis polysaccharides can improve the stability and reduce the toxicity of selenium nanoparticles. It can lay the foundation for the comprehensive utilization of S. platensis and the development and research of polysaccharide nano-selenium complexes.