Chen Yen-Wei, Drury Jeanie L, Chung Whasun Oh, Hobbs David T, Wataha John C
Department of Restorative Dentistry, University of Washington School of Dentistry, USA.
Department of Restorative Dentistry, University of Washington School of Dentistry, USA ; Department of Oral Health Sciences, University of Washington School of Dentistry, USA.
Int J Med Nano Res. 2015;2(1). doi: 10.23937/2378-3664/1410009. Epub 2015 Jun 13.
Metal ions are notorious environmental contaminants, some causing toxicity at exquisitely low (ppm-level) concentrations. Yet, the redox properties of metal ions make them attractive candidates for bio-therapeutics. Titanates are insoluble particulate compounds of titanium and oxygen with crystalline surfaces that bind metal ions; these compounds offer a means to scavenge metal ions in environmental contexts or deliver them in therapeutic contexts while limiting systemic exposure and toxicity. In either application, the toxicological properties of titanates are crucial. To date, the accurate measurement of the toxicity of titanates has been complicated by their particulate nature, which interferes with many assays that are optical density (OD)-dependent, and at present, little to no titanate toxicity data exist. Compatibility data garnered thus far for native titanates are inconsistent and lacking in mechanistic understanding. These data suggest that native titanates have little toxicity toward several oral and skin bacteria species, but do suppress mammalian cell metabolism in a cells-pecific manner. Titanate compounds bind several types of metal ions, including some common environmental toxins, and enhance delivery to bacteria or cells. Substantial work remains to address the practical applicability of titanates. Nevertheless, titanates have promise to serve as novel vehicles for metal-based therapeutics or as a new class of metal scavengers for environmental applications.
金属离子是臭名昭著的环境污染物，有些在极低（ppm级）浓度下就会产生毒性。然而，金属离子的氧化还原特性使其成为生物治疗的有吸引力的候选物。钛酸盐是钛和氧的不溶性颗粒化合物，其晶体表面能结合金属离子；这些化合物提供了一种在环境中清除金属离子或在治疗环境中输送金属离子的方法，同时限制全身暴露和毒性。在任何一种应用中，钛酸盐的毒理学特性都至关重要。迄今为止，由于钛酸盐的颗粒性质干扰了许多依赖光密度（OD）的检测方法，使得准确测量钛酸盐的毒性变得复杂，目前几乎没有钛酸盐毒性数据。到目前为止获得的关于天然钛酸盐的兼容性数据并不一致，且缺乏机理理解。这些数据表明，天然钛酸盐对几种口腔和皮肤细菌几乎没有毒性，但确实以细胞特异性方式抑制哺乳动物细胞代谢。钛酸盐化合物能结合多种类型的金属离子，包括一些常见的环境毒素，并增强向细菌或细胞的递送。要解决钛酸盐的实际适用性，仍有大量工作要做。尽管如此，钛酸盐有望成为基于金属的治疗药物的新型载体，或成为环境应用中的一类新型金属清除剂。
