Effect of degree of substitution of octenyl succinate on starch micelles for synthesis and stability of selenium nanoparticles: Towards selenium supplements

To develop a promising selenium supplement that overcomes the instability and poor water dispersibility of selenium nanoparticles (SeNPs), we synthesized a series of amphiphilic octenyl succinic anhydride starch (OSAS) through esterification. As the degree of substitution (DS) increased, the particle size of OSAS micelles and the critical micelle concentration (CMC) decreased. FTIR and XRD analysis confirmed the successful introduction of octenyl succinic anhydride groups onto starch. Subsequently, OSAS micelles were used as carriers to synthesize SeNPs via in situ chemical reduction, forming SeNPs-loaded self-assembled starch nano-micelles (OSAS-SeNPs). The OSAS-SeNPs exhibited spherical dispersion in water with an average diameter of 116.1 ± 2.3 nm, contributed to enhanced hydrophobic interactions. TEM images showed a core-shell structure with SeNPs as the core and OSAS as the shell. FTIR results indicated hydrogen bonding interactions between OSAS and SeNPs. Due to the negatively charged OSAS shell and hydrogen bonding (OH⋯Se), OSAS-SeNPs remained non-aggregated for one month at room temperature, demonstrating remarkable stability. This study suggests that using OSAS can address the synthesis and stability issues of SeNPs, making it a potential selenium supplement candidate for further evaluation as an anticancer agent. Selenium nanoparticles (SeNPs) tend to aggregate at room temperature and thus became inactive. Self-assembled OSAS micelles for the encapsulation of SeNPs were synthesized by in situ chemical methods by taking advantage of the amphiphilic structure of OSA starch, and the obtained OSAS-SeNPs had good stability. [Display omitted] •Self-assembled OSA starch micelle loaded with SeNPs was successfully constructed.•Effect of DS of OSA starch for synthesis and stability of SeNPs was elucidated.•Because of the good stability, the OSAS-SeNPs did not cluster together for a month.