Bioinspired Eggosomes with Dual Stimuli-Responsiveness.

Hen's eggs have been designed through evolution to serve as a rich source of nutrients and to provide a protective environment for the developing embryo. As such, they have a unique composition and structural organization, consisting of an egg yolk, egg white, and eggshell. Inspired by nature, a biomimetic approach has been adopted in this study to create "micro-eggs" using the natural structure of hen's eggs as an inspiration. Our aim was to use these micro-eggs to encapsulate, protect, and release nutrients so they could be incorporated into functional foods to improve their nutritional value. These micro-eggs consist of an oily core surrounded by a protein-rich gel, which is then coated by a hard calcium carbonate (CaCO) shell. Advanced emulsion technology and structural design principles were utilized to create these microscale egg-like structures (50-200 μm). In particular, a water-in-oil-in-water (W/O/W) double emulsion was formulated using natural materials found in eggs (lecithin, oleic acid, and albumin) to create the egg yolk/egg white structure. Then, a CaCO "eggshell" was fabricated to stabilize the outer oil-water interface. The resulting micro-eggs were then successfully packaged into an "egg box" formed by calcium alginate. The packaged micro-eggs were shown to have good resistance to disruption or separation during storage. The thermo- and pH-responsive "egg yolk" was provided bioactive release "on-demand". We refer to these biomimetic micro-eggs as "eggosomes" in analogy to colloidosomes. The nutritionally fortified eggosomes developed here may be useful for the creation of functional foods specifically designed to improve human health and wellbeing.