Department of Oncology, The First Affiliated Hospital, Department of Chemistry, Jinan University, Guangzhou, 510632, China.
J Nanobiotechnology. 2021 Mar 4;19(1):67. doi: 10.1186/s12951-021-00807-6.
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.
Herein, a type of edible oil-in-water Pickering emulsion was structured by calcium carbonate nanoparticles (CaCO 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 CaCO NPs stabilized Pickering emulsion can be controlled by varying the particle concentration (c) and oil volume fraction (φ). The emulsification stabilizing capability of the CaCO 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 CaCO NP-based Pickering emulsion displayed acid-trigged demulsification because of the disintegration of the CaCO NPs into Ca 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.
Taken together, the rationally designed CaCO NP emulsion system holds potential as a calcium-fortified formulation for food, pharmaceutical and biomedical applications.
由食品级碳酸钙组装而成的纳米颗粒因其生物相容性、可消化性、颗粒和表面特性（如大小、表面积和部分润湿性）以及其酸易分解性质提供的刺激响应性而受到关注。
本文构建了一种油包水型碳酸钙纳米颗粒（CaCO NPs；平均粒径：80nm）和中链甘油三酯（MCT）稳定的Pickering 乳液，用于递送疏水性药物和同时口服补充钙。所制得的 CaCO NPs 稳定的 Pickering 乳液的微观结构可以通过改变颗粒浓度（c）和油体积分数（φ）来控制。CaCO NPs 的乳化稳定能力还有利于在高φ（0.7-0.8）下形成高内相乳液，并在室温下和 4°C 下具有优异的乳液稳定性，从而保护包裹的疏水性生物活性维生素 D3（VD3）免受降解。有趣的是，由于在模拟胃环境中 CaCO NPs 分解为 Ca，在基于结构化 CaCO NP 的 Pickering 乳液中显示出酸触发的破乳作用，随后在模拟肠液中脂质发生有效的脂解作用。通过乳液的包封和递送，VD3 在模拟胃肠道消化后表现出令人满意的生物利用度。
综上所述，合理设计的 CaCO NP 乳液系统有望成为食品、制药和生物医学应用的强化钙配方。
