A novel sunflower-like nanocarrier based on dual milk-derived proteins for improved bio-accessibility, stability and antioxidant activity of anthocyanin

Anthocyanin (ACN), as a hydrophilic compound, has excellent antioxidant and anti-inflammatory biological activities, but its poor stability and low bioavailability limit widespread application in the food industry. In the current study, a novel nanocarrier based "one stone for multiple birds" response strategy was designed to enhance the in vitro bio-accessibility, targeting capabilities, and antioxidant activity of ACN. The forementioned strategy entailed the utilization of triphenylphosphonium bromide (TPP)-modified dual-natural milk-derived proteins (WPCA)-fucoidan (FD) conjugates as a wall material via an amide reaction. Subsequently, ACN-loaded nanocarriers were prepared by assembly assisted with ultrasound method through hydrogen bonding, ionic complexation, and hydrophobic interaction. Transmission electron microscopy revealed that the nanocarriers exhibited a sunflower-like shape with a size of around 936 nm (7 mg/mL of ACN). Exhilaratingly, a sunflower-like nanocarrier (SNC) achieved dual pH- and redox-responsive release in the presence of 10 mM of glutathione (GSH) at pH 7.4, exhibiting intestine-responsive release behavior, high bio-accessibility, environmental stability, colon-targeting safety. Meanwhile, the nanocarrier demonstrated superior targeting of mitochondria, as evidenced by a Pearson's correlation coefficient of 0.80 at 6 h. In vitro cell experiments showed that the ACN-loaded SNC significantly effectively suppressed the generation of ROS and mitochondrial depolarization caused by oxidative stress. These findings hold significant importance in the potential ability of the anthocyanin-loaded natural bioactive nanocarriers, particularly and can potentially mitigate exogenous oxidative stress effectively.