title: Titanates and Titanate-Metal Compounds in Biological Contexts.
abstract: 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 thein vitrotoxicity 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 noin vivotitanate toxicity data exist. Compatibility data garnered thus far for native titanatesin vitroare 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.
authors.affiliation: Department of Restorative Dentistry, University of Washington School of Dentistry, USA.
authors.forename: Yen-Wei
authors.initials: YW
authors.lastname: Chen
authors.affiliation: Department of Restorative Dentistry, University of Washington School of Dentistry, USA ; Department of Oral Health Sciences, University of Washington School of Dentistry, USA.
authors.forename: Jeanie L
authors.initials: JL
authors.lastname: Drury
authors.affiliation: Department of Oral Health Sciences, University of Washington School of Dentistry, USA.
authors.forename: Whasun Oh
authors.initials: WO
authors.lastname: Chung
authors.affiliation: Savannah River National Laboratory, USA.
authors.forename: David T
authors.initials: DT
authors.lastname: Hobbs
authors.affiliation: Department of Restorative Dentistry, University of Washington School of Dentistry, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Wataha
keywords: Antibiotics; Biocompatibility; Cancer; Drug-delivery; Environmental cleanup; Titanates and titanate-metal compounds