Synthesis, characterization, biological activity, and in vitro digestion of selenium nanoparticles stabilized by Antarctic ice microalgae polypeptide.

[Display omitted] • An efficient unreported ultrasound-assisted enzymatic method was used for the extraction of AIMP. • AIMP as a modifier can significantly adjust the particle size of SeNPs. • The gastrointestinal stability of AIMP-SeNPs is significantly better than that of SeNPs. • AIMP-SeNPs have a significant inhibitory effect on bacteria by destroying their structure. A new type of uniformly dispersed selenium nanoparticles (SeNPs) was prepared using Antarctic ice microalgae polypeptides (AIMP) as the stabilizer and dispersant. Different characterization techniques and tests show that the SeNPs are effectively combined with AIMP through physical adsorption and hydrogen bonding to form a more stable structure. Orange-red, zero-valence, amorphous, and spherical AIMP-SeNPs with a diameter of 52.07 ± 1.011 nm and a zeta potential of −41.41 ± 0.882 mV were successfully prepared under the optimal conditions. The AIMP-SeNPs had significantly higher DPPH, ABTS and hydroxyl radicals scavenging abilities compared with AIMP and Na 2 SeO 3 , and prevented the growth of both Gram-negative and Gram-positive bacteria by disrupting the integrity of cell walls, cell membranes and mitochondrial membranes. The AIMP-SeNPs had higher gastrointestinal stability compared with SeNPs. Thus, this research highlights the crucial role of AIMP as a biopolymer framework in the dispersion, stabilization, and size management of SeNPs and concludes that AIMP-SeNPs can be exploited as a potent antioxidant supplement and antibacterial substance in foods and medicine. [ABSTRACT FROM AUTHOR]