Corn starch/β-Cyclodextrin composite nanoparticles for encapsulation of tea polyphenol and development of oral targeted delivery systems with pH-responsive properties

The development of nano-encapsulated materials with responsive properties for oral targeted delivery systems is innovative and promising. The aim of this study using corn starch (CS) and β-cyclodextrin (β-CD) to prepare composite nanoparticles (CNPs) that can efficiently encapsulate Tea polyphenol (-)-Epigallocatechin gallate (EGCG) with pH-responsive properties for targeted delivery. The results demonstrated that the CNPs prepared with a 1:1 mass ratio of CS and β-CD exhibited excellent stability to pH, ionic concentration, heating and storage conditions, which was mainly driven by hydrogen bonding and hydrophobic interactions. The characterization results showed that tea polyphenol was effectively loaded into the CNPs and the encapsulation and loading rates were 86.96% and 10.87%, respectively. The CNPs encapsulated tea polyphenol exhibited excellent photothermal stability and maintained significant antioxidant activity after 15 days. Additionally, bio-accessibility experiments revealed that the CNPs can resist low pH environments, can be fully released and reach the target site under alkaline conditions, with potential pH-responsive and intestinal-targeted delivery properties. Overall, the CNPs prepared in this study will support to develop pH-responsive characterization of oral targeted delivery systems for the food industry and biomedicine fields.