Synthesis and characterization of anthocyanin-loaded bovine serum albumin nanoparticles: unveiling the encapsulation mechanisms with computational insights.

Background: Black rice anthocyanins (BRA) offer significant health benefits but are limited in application due to their low bioavailability. Bovine serum albumin (BSA) nanoparticles (NPs) have been shown to effectively enhance the stability of encapsulated BRA. However, the mechanism of BRA-BSA NP formation and their molecular interactions remain unclear. This study prepared and characterized BRA-BSA NPs and investigated the formation mechanisms using computational simulations.

Results: The optimized BRA-BSA NPs had a particle size of 128.37 ± 4.10 nm, a zeta potential of -18.93 ± 0.32 mV and an encapsulation efficiency of 81.10 ± 0.08%. Characterization showed that the NPs were stabilized through hydrophobic interactions and hydrogen bonds. BRA-BSA NPs exhibited a slow release in the upper gastrointestinal tract. Molecular dynamics simulations, both all-atom and coarse-grained, revealed that anthocyanins bound to four primary sites on the BSA surface through hydrogen bonds and van der Waals forces. Furthermore, ethanol was shown to modulate the dissociation of amino acids, promoting BSA aggregation and self-assembly into NPs.

Conclusion: The results demonstrate that BSA NPs loaded with BRA serve as effective carriers with high encapsulation efficiency. Molecular dynamics simulations elucidated the molecular basis of cyanidin-3-O-glucoside-BSA interactions, as well as the self-assembly process of BSA. This study therefore provides valuable insights for developing BSA-based delivery systems for BRA, advancing the fields of bioactive encapsulation of nutraceuticals. © 2025 Society of Chemical Industry.