Kim Mi-Kyung, Lee Jeong-A, Jo Mi-Rae, Kim Min-Kyu, Kim Hyoung-Mi, Oh Jae-Min, Song Nam Woong, Choi Soo-Jin
Department of Food Science and Technology, Seoul Women's University, 621 Hwarang-ro, Nowon-gu, Seoul 139-774, Korea.
Department of Chemistry and Medical Chemistry, College of Science and Technology, 1 Yonseidaegil, Wonju, Gangwondo 220-710, Korea.
Nanomaterials (Basel). 2015 Nov 10;5(4):1938-1954. doi: 10.3390/nano5041938.
Calcium is the most abundant mineral in human body and essential for the formation and maintenance of bones and teeth as well as diverse cellular functions. Calcium carbonate (CaCO₃) is widely used as a dietary supplement; however, oral absorption efficiency of CaCO₃ is extremely low, which may be overcome by applying nano-sized materials. In this study, we evaluated the efficacy of food grade nano CaCO₃ in comparison with that of bulk- or reagent grade nano CaCO₃ in terms of cytotoxicity, cellular uptake, intestinal transport, and oral absorption. Cytotoxicity results demonstrated that nano-sized CaCO₃ particles were slightly more toxic than bulk materials in terms of oxidative stress and membrane damage. Cellular uptake behaviors of CaCO₃ nanoparticles were different from bulk CaCO₃ or Ca ions in human intestinal epithelial cells, showing efficient cellular internalization and elevated intracellular Ca levels. Meanwhile, CaCO₃ nanoparticles were efficiently transported by microfold (M) cells model of human intestinal follicle-associated epithelium, in a similar manner as Ca ions did. Biokinetic study revealed that the biological fate of CaCO₃ particles was different from Ca ions; however, , its oral absorption was not significantly affected by particle size. These findings provide crucial information to understand and predict potential toxicity and oral absorption efficiency of food grade nanoparticles.
钙是人体中含量最丰富的矿物质，对骨骼和牙齿的形成与维持以及多种细胞功能至关重要。碳酸钙（CaCO₃）被广泛用作膳食补充剂；然而，碳酸钙的口服吸收效率极低，应用纳米材料或许可以克服这一问题。在本研究中，我们从细胞毒性、细胞摄取、肠道转运和口服吸收方面评估了食品级纳米碳酸钙与块状或试剂级纳米碳酸钙的功效。细胞毒性结果表明，就氧化应激和膜损伤而言，纳米级碳酸钙颗粒的毒性略高于块状材料。碳酸钙纳米颗粒在人肠上皮细胞中的细胞摄取行为不同于块状碳酸钙或钙离子，表现出高效的细胞内化和细胞内钙水平升高。同时，碳酸钙纳米颗粒通过人肠滤泡相关上皮的微褶（M）细胞模型进行有效转运，其方式与钙离子类似。生物动力学研究表明，碳酸钙颗粒的生物学归宿与钙离子不同；然而，其口服吸收并未受到颗粒大小的显著影响。这些发现为理解和预测食品级纳米颗粒的潜在毒性和口服吸收效率提供了关键信息。
