Background
Nanoparticles assembled from food-grade calcium carbonate have attracted attention because of their biocompatibility, digestibility, particle and surface features (such as size, surface area, and partial wettability), and stimuli-responsiveness offered by their acid-labile nature.
Conclusions
Taken together, the rationally designed CaCO3 NP emulsion system holds potential as a calcium-fortified formulation for food, pharmaceutical and biomedical applications.
Results
Herein, a type of edible oil-in-water Pickering emulsion was structured by calcium carbonate nanoparticles (CaCO3 NPs; mean particle size: 80 nm) and medium-chain triglyceride (MCT) for delivery of lipophilic drugs and simultaneous oral supplementation of calcium. The microstructure of the as-made CaCO3 NPs stabilized Pickering emulsion can be controlled by varying the particle concentration (c) and oil volume fraction (φ). The emulsification stabilizing capability of the CaCO3 NPs also favored the formation of high internal phase emulsion at a high φ of 0.7-0.8 with excellent emulsion stability at room temperature and at 4 °C, thus protecting the encapsulated lipophilic bioactive, vitamin D3 (VD3), against degradation. Interestingly, the structured CaCO3 NP-based Pickering emulsion displayed acid-trigged demulsification because of the disintegration of the CaCO3 NPs into Ca2+ in a simulated gastric environment, followed by efficient lipolysis of the lipid in simulated intestinal fluid. With the encapsulation and delivery of the emulsion, VD3 exhibited satisfying bioavailability after simulated gastrointestinal digestion. Conclusions: Taken together, the rationally designed CaCO3 NP emulsion system holds potential as a calcium-fortified formulation for food, pharmaceutical and biomedical applications.