Cyclodextrin-Based Pickering Emulsion Significantly Increases 6-Gingerol Loading Through Two Different Mechanisms: Cyclodextrin Cavity and Pickering Core.

We previously found that host-guest interactions can drive gingerols (Gs) and cyclodextrins (CDs) together to form inclusion complexes (G/CD), which can further construct amphiphilic microcrystals and resultant Pickering emulsions through self-assembly. In this follow-up study, we explored the detailed formation processes and mechanisms of the 6-G/β-CD inclusion complex and the resultant Pickering emulsion. The influence of the 6-G/β-CD molar ratio on the structure, morphology, and loading capacity of the inclusion complex and resultant Pickering emulsion were investigated. The results show that the cyclodextrin-based Pickering emulsion can load 6-G in two places; one place is the cyclodextrin cavity, whose loading capacity is up to 9.28%, while the other one is the Pickering core, with its highest loading capacity at 32.31% when the 6-G/β-CD molar ratio is 5:1. In the above case, the 6-G/β-CD inclusion complex was found to form a unit cell with a 1:2 molar ratio and then self-assemble into amphiphilic microcrystals through cage-type arrangement structures at the oil-water interface, mainly driven by van der Waals forces and hydrogen bonds. This study is helpful in the design and preparation of CD-based high-loading carriers for bioactive compound delivery.