Encapsulation of anthocyanin molecules within a ferritin nanocage increases their stability and cell uptake efficiency

Anthocyanins are very spectacular plant pigments with many biological activities. However, because of their highly reactive nature, anthocyanins are unstable. We developed a novel strategy for improving the thermal stability and photostability of cyanidin-3-O-glucoside (C3G) molecules by encapsulating them within the inner cavity of apo recombinant soybean seed H-2 subunit ferritin (rH-2). C3G molecules were successfully encapsulated within protein cages with a C3G/protein ratio of 37.5 to 1. As expected, such encapsulation increased the thermal stability and photostability of C3G molecules by a factor of ~ 2. More importantly, Caco-2 cell monolayer absorption and adhesion analyses showed that C3G molecules encapsulated within apoferritin nanocages were more efficient in transport as compared to free C3G. These findings indicate that protein with a shell-like structure as a nanoplatform can play an important role in the field of nutrition.