Bischoff Nicolaj S, Undas Anna K, van Bemmel Greet, Briedé Jacco J, van Breda Simone G, Verhoeven Jessica, Verbruggen Sanne, Venema Koen, Sijm Dick T H M, de Kok Theo M
Department of Translational Genomics, GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands.
Wageningen Food Safety Research (WFSR), Wageningen University & Research, 6708 WB Wageningen, The Netherlands.
Nanomaterials (Basel). 2024 Dec 25;15(1):8. doi: 10.3390/nano15010008.
Food-grade titanium dioxide (E171) is widely used in food, feed, and pharmaceuticals for its opacifying and coloring properties. This study investigates the formation of reactive oxygen species (ROS) and the aggregation behavior of E171 using the TNO Gastrointestinal (GI) model, which simulates the stomach and small intestine. E171 was characterized using multiple techniques, including electron spin resonance spectroscopy, single-particle inductively coupled plasma-mass spectrometry, transmission electron microscopy, and dynamic light scattering. In an aqueous dispersion (E171-aq), E171 displayed a median particle size of 79 nm, with 73-75% of particles in the nano-size range (<100 nm), and significantly increased ROS production at concentrations of 0.22 and 20 mg/mL. In contrast, when E171 was mixed with yogurt (E171-yog), the particle size increased to 330 nm, with only 20% of nanoparticles, and ROS production was inhibited entirely. After GI digestion, the size of dE171-aq increased to 330 nm, while dE171-yog decreased to 290 nm, with both conditions showing a strongly reduced nanoparticle fraction. ROS formation was inhibited post-digestion in this cell-free environment, likely due to increased particle aggregation and protein corona formation. These findings highlight the innate potential of E171 to induce ROS and the need to consider GI digestion and food matrices in the hazard identification/characterization and risk assessment of E171.
食品级二氧化钛（E171）因其遮光和着色特性而广泛应用于食品、饲料和药品中。本研究使用模拟胃和小肠的TNO胃肠道（GI）模型，研究了E171的活性氧（ROS）形成和聚集行为。使用多种技术对E171进行了表征，包括电子自旋共振光谱、单颗粒电感耦合等离子体质谱、透射电子显微镜和动态光散射。在水分散体（E171-aq）中，E171的中位粒径为79 nm，73-75%的颗粒在纳米尺寸范围内（<100 nm），在浓度为0.22和20 mg/mL时ROS生成显著增加。相比之下，当E171与酸奶混合（E171-yog）时，粒径增加到330 nm，只有20%的纳米颗粒，并且ROS生成完全受到抑制。经过胃肠道消化后，dE171-aq的尺寸增加到330 nm，而dE171-yog的尺寸减小到290 nm，两种情况下纳米颗粒比例均大幅降低。在这种无细胞环境中，消化后ROS形成受到抑制，这可能是由于颗粒聚集增加和蛋白质冠形成。这些发现突出了E171诱导ROS的内在潜力，以及在E171的危害识别/表征和风险评估中考虑胃肠道消化和食物基质的必要性。
