Molecular Sciences Institute, School of Chemistry, University of Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa; Toxicology and Biochemistry Department, National Institute for Occupational Health, A Division of National Health Laboratories, Johannesburg, South Africa.
Molecular Sciences Institute, School of Chemistry, University of Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa.
Toxicol In Vitro. 2022 Oct;84:105457. doi: 10.1016/j.tiv.2022.105457. Epub 2022 Aug 18.
Investigating the biodurability and persistence of titanium dioxide nanoparticles (TiO NPs) is of paramount importance because these parameters influence the particles' impact on human health and the environment. Contrary to most research conducted so far, the present study elucidates the dissolution kinetics, namely the dissolution rates, rate constants, order of reaction and half-times of TiO NPs in five different simulated biological fluids and two synthetic environmental media to predict their behaviour in real life situations. Results have shown that the dissolution of TiO NPs in all simulated fluids was limited. Of all the simulated biological media tested, acidic media such as phagolysosomal and gastric fluid produced the highest dissolution of TiO NPs compared to alkaline media such as blood plasma, Gamble's fluid, and intestinal fluid. Furthermore, when the particles were exposed to simulated environmental conditions, the dissolution was higher in high ionic strength seawater compared to freshwater. The dissolution kinetics of titanium dioxide nanoparticles followed first order reaction kinetics and were generally characterized by low dissolution rates and long half-times. These findings indicate that TiO NPs are very insoluble and will remain unchanged in the body and environment over long periods of time. Therefore, these particles are most likely to cause both short and long-term health effects and will remain persistent following release into the environment.
研究二氧化钛纳米粒子（TiO NPs）的生物持久性非常重要，因为这些参数会影响这些粒子对人类健康和环境的影响。与迄今为止进行的大多数研究不同，本研究阐明了溶解动力学，即 TiO NPs 在五种不同模拟生物流体和两种合成环境介质中的溶解速率、速率常数、反应级数和半衰期，以预测它们在实际情况下的行为。结果表明，TiO NPs 在所有模拟流体中的溶解都受到限制。在所有测试的模拟生物介质中，与碱性介质（如血浆、Gamble 液和肠液）相比，酸性介质（如吞噬体和胃液）产生了 TiO NPs 的最高溶解。此外，当颗粒暴露于模拟环境条件时，高离子强度海水中的溶解率高于淡水。TiO NPs 的溶解动力学遵循一级反应动力学，通常具有低溶解速率和长半衰期的特征。这些发现表明 TiO NPs 非常难溶，在体内和环境中长时间内将保持不变。因此，这些粒子极有可能导致短期和长期的健康影响，并在释放到环境中后保持持久性。
