Nanocarrier from water extract solution of Auricularia auricula for zinc delivery

Food-borne nanoparticles (FNs) may have potential for microelement delivery due to their good biocompatibility and healthy benefits. In this paper, hydrophilic FNs with ultra-small size of 1.7 nm were prepared from the water extract solution of Auricularia auricula by hydrothermal method. The structural characterization showed that Zn(II)-FNs were formed after the interaction of abundant functional groups like amino, hydroxyl, and carboxyl functional groups on the surface of FNs with Zn²⁺. The Zn(II)-FNs showed better cell compatibility than ZnSO₄ and zinc gluconate with no visible cytotoxicity at concentrations up to 75 μg/mL for the normal rat kidney cells. Less than 5% hemolysis rate was found when the concentration of Zn(II)-FNs was 5 mg/mL after incubation for 3h. The biodistribution experiments indicated that Zn(II)-FNs had no obvious toxic effect after being orally administrated at a dose of 500 mg/kg mouse body weight, and Zn(II)-FNs were present in the stomach, intestine, lung, liver, and kidney. Our data indicated that FNs collected from Auricularia auricula water extract solution might act as a safe and effective nanocarrier for Zn(II).