Ulvan polysaccharide stabilized selenium nanoparticles: synthesis and antidiabetic ability

Abstract Ulvan is a sulfated polysaccharide extracted from green seaweed and has been used in several studies for the green synthesis of selenium nanoparticles (SeNPs). This study aims to comparatively evaluate pure SeNPs and ulvan capped SeNPs (UP-SeNPs) to identify the specific role of ulvan in nanoparticle formation and its influence on the characteristics of SeNPs, which have rarely been clarified in previous studies, and to explore their antidiabetic potential, an application not previously reported for this system. SeNPs were synthesized using ulvan as a capping and stabilizing agent and characterized by standard physicochemical techniques. Antidiabetic activity was assessed through α -glucosidase and α -amylase inhibition assays. The obtained results showed that UP molecules effectively capped the SeNPs surface via hydrogen bonding and electrostatic or coordination interactions, thereby restricting particle growth and improving dispersion. UP-SeNPs exhibited smaller particle sizes, with a DLS determined hydrodynamic diameter of 128.64 nm, and significantly higher stability, as indicated by a zeta potential of −25.6 mV, compared with pure SeNPs (184.11 nm and −8.7 mV, respectively. UP-SeNPs also demonstrated markedly enhanced inhibitory activity against α -glucosidase and α -amylase, with IC 50 values of 34.56 and 57.89 μg ml −1 , whereas pure SeNPs displayed negligible inhibition within the tested concentration range. These findings highlight the crucial role of ulvan in improving the physicochemical properties of SeNPs-particularly particle size distribution, surface charge, and stability - which in turn enhances their antidiabetic activity. This study demonstrates the value of ulvan as a natural, biocompatible stabilizer capable of improving both the material properties and biological performance of SeNPs.