Precision assembly of ethyl cellulose-zein Janus nanoparticles with lock-and-key structures for controlled release of quercetin and curcumin.

Janus nanoparticles have attracted widespread attention in co-delivery and controlled release of nutraceuticals due to their anisotropic composition and properties. This study reported a novel method for preparing ethyl cellulose-zein Janus nanoparticles loaded with quercetin and curcumin. Morphological observations indicated that the Maillard reaction-mediated nanoprecipitation method successfully prepared Janus nanoparticles with lock-and-key structures. Multispectral technology and three-phase interfacial tension principle further confirmed the formation of Janus nanoparticles. Notably, the glycosylated bridge generated in the Maillard reaction played a crucial role in the formation of Janus nanoparticles. It enhanced the interface coupling between ethyl cellulose and zein, thus promoting the formation of Janus nanoparticles. Compared with single nanoparticles, Janus nanoparticles exhibited better thermal, storage, and physical stability, which was beneficial for their application in the food industry. It was found that Janus NPs could regionally encapsulate quercetin and curcumin in the EC hemisphere and zein sphere. In vitro digestion experiments indicated that Que/Cur-loaded Janus NPs could achieve the controlled release of quercetin and curcumin in the small intestine and colon, respectively. This study not only offers an idea for synthesizing food-grade Janus nanoparticles but also provides new insights into co-delivery and controlled release of nutraceuticals.