Release of calcium ions from particulate monosodium titanates for dental mineralization applications.

Purpose: The calcium ion [Ca(II)] release from monosodium titanates (MST) complexed to calcium ions [Ca(II)], referred to as MST-Ca(II), was examined under varying incubation times, pH conditions, and ion equilibrium disruptions.

Methods: Sample supernatants were analyzed for Ca(II) using the QuantiChrom Calcium Assay Kit.

Results: No Ca(II) was detected in native MST (control) supernatants but was detected in MST-Ca(II) supernatants.

Cytotoxicity of Titanate-Calcium Complexes to MC3T3 Osteoblast-Like Cells.

Monosodium titanates (MST) are a relatively novel form of particulate titanium dioxide that have been proposed for biological use as metal sorbents or delivery agents, most recently calcium (II). In these roles, the toxicity of the titanate or its metal complex is crucial to its biological utility. The aim of this study was to determine the cytotoxicity of MST and MST-calcium complexes with MC3T3 osteoblast-like cells; MST-Ca(II) complexes could be useful to promote bone formation in various hard tissue applications.

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate.

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150 nm.

Titanates and Titanate-Metal Compounds in Biological Contexts.

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.

Plasma filtering techniques for nuclear waste remediation.

Nuclear waste cleanup is challenged by the handling of feed stocks that are both unknown and complex. Plasma filtering, operating on dissociated elements, offers advantages over chemical methods in processing such wastes. The costs incurred by plasma mass filtering for nuclear waste pretreatment, before ultimate disposal, are similar to those for chemical pretreatment.

Evaluation of tertiary pyridine resin for the separation of lanthanides by simulated moving-bed chromatography.

Lanthanide separation by simulated moving-bed chromatography was studied as a model system for separating lanthanide fission products and minor actinides from used nuclear fuels. The simulated moving-bed system was modeled for a tertiary pyridine anion-exchange resin supported on silica particles as the stationary phase and a mixture of methanol and 1 M nitric acid as the mobile phase. Pulse injection tests using a single packed column were used to obtain chromatographic parameters for mathematical modeling of the simulated moving-bed system.

In vitro biological response of micro- and nano-sized monosodium titanates and titanate-metal compounds.

Previous studies report that microsized monosodium titanates (MSTs) deliver metal ions and species to mammalian cells and bacteria with cell-specific and metal-specific effects. In this study, we explored the use of MST and a new synthesized nanosized monosodium titanate (nMST) to deliver gold(III), cisplatin, or platinum(IV) to two human cell lines with different population doubling times, in vitro. The effect was measured using a fluorescent mitochondrial activity assay (CellTiter-Blue(®) Assay).

Separation of americium from curium by oxidation and ion exchange.

Nuclear energy has the potential to be a clean alternative to fossil fuels, but in order for it to play a major role in the US, many questions about the back end of the fuel cycle must be addressed. One of these questions is the difficult separation of americium from curium. Here, we report the oxidation of Am in two systems, perchloric acid and nitric acid and the affect of changing the acid has on the oxidation.

Peroxotitanate- and monosodium metal-titanate compounds as inhibitors of bacterial growth.

Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents.

Titanates deliver metal ions to human monocytes.

Amorphous peroxotitantes (APT) are insoluble titanium-based particles that bind a variety of metal compounds with high affinity; these particles could be sequestered locally in a solid phase to deliver metal-based drugs. Previous studies have confirmed the 'biodelivery' of metals from metal-APT complexes to fibroblasts, but not monocytes. Our goal in the current study was to use monocytic cytokine secretion to assess delivery of gold or platinum-based compounds from APT to human THP1 monocytes.

Peroxotitanates for biodelivery of metals.

Metal-based drugs are largely undeveloped in pharmacology. One limiting factor is the systemic toxicity of metal-based compounds. A solid-phase, sequestratable delivery agent for local delivery of metals could reduce systemic toxicity, facilitating new drug development in this nascent area.

Titanate particles as agents to deliver gold compounds to fibroblasts and monocytes.

Titanates are inorganic compounds with high affinity for specific metal ions or metal compounds, including gold. We have previously demonstrated that both monosodium titanate (MST) and amorphous peroxo-titanate (APT) alone do not suppress cellular metabolism of several cell types, and we have shown that MST and APT adsorb and release gold compounds in biological salt solutions. In the current study, we extend this work and show that MST and APT loaded with two gold compounds deliver sufficient levels of these compounds to alter the metabolism of mammalian cells.