Bio-inorganic microcapsules from templating protein- and bionanoparticle-stabilized Pickering emulsions

We hereby propose a novel method for the preparation of (bio-) inorganic microcapsules. Protein-stabilized oil-in-water Pickering emulsions formed a versatile scaffold for the mineralization with calcium phosphate. All reactions were performed at room temperature or 37 °C, respectively, and pH = 7.4. Different mineralization solutions, among them a simulated body fluid (SBF) for mimicking physiological conditions, gave different patterns of mineralization. Particularly, ferritin stabilized Pickering emulsions showed a slow nucleation and mineralization process. The formation of thin and rigid mineral shells could be readily achieved. We present a straightforward and at the same time extremely versatile approach here, which opens a new route to the preparation of hybrid materials with different hierarchical levels. These materials could find interesting applications in biomedicine, for cosmetic formulations or in food technology. Protein and bionanoparticle stabilized Pickering oil-in-water emulsions were used as a versatile scaffold for the synthesis of bio-inorganic hybrid capsules through mineralization with calcium phosphate. Different (biomimetic) mineralization procedures allowed us to control the capsule shell thickness and morphology.