Enzymatically hydrolyzed sodium caseinate nanoparticles efficiently enhancing the solubility, stability, and antioxidant and anti-biofilm activities of hydrophobic Tanshinone IIA

Enzymatic hydrolysis has been validated as an appropriate strategy for improving the properties of natural protein. Here, we used enzymatic hydrolysis sodium caseinate (Eh NaCas) as a nano-carrier for enhancing the solubility, stability, and antioxidant and anti-biofilm activities of hydrophobic encapsulants. Tanshinone IIA (TA) was loaded into the hydrophobic regions of Eh NaCas by self-assembly, and the encapsulation efficiency could reach 96.54 ± 0.14% under an optimized host–guest ratio. After Eh NaCas packed, the TA-loaded Eh NaCas nanoparticles (Eh NaCas@TA) showed regular spheres, uniform particle size distribution and more optimal drug release. Moreover, the solubility of TA in aqueous solution increased over 2.4 × 105 times, and the TA guest molecules displayed excellent stability under light and other harsh environments. Interestingly, the vehicle protein and TA exhibited synergistic antioxidant effects. Furthermore, Eh NaCas@TA forcefully restrained the growth and destroyed the biofilm construction of Streptococcus mutans compared to free TA, showing positive antibacterial activity. The establishment of these results demonstrated the feasibility and functionality of edible protein hydrolysates as nano-carriers for loading natural plant hydrophobic extracts.