Titanates deliver metal ions to human monocytes

Abstract

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. Cytokine secretion was not triggered by APT alone or metal-APT complexes. In monocytes activated by lipopolysaccharide (LPS), APT alone enhanced or suppressed IL1beta or IL6 secretion, yet TNFalpha secretion was unaffected. Complexes of APT and Au(III) or cis-platin altered LPS-activated IL6 or IL1beta secretion most, TNFalpha least. Our results suggest that the APT deliver metals to monocytes.

Metallic ions as therapeutic agents in tissue engineering scaffolds: an overview of their biological applications and strategies for new developments

“…Despite the efforts made in this respect, the achievements in controlling and sustaining the release of loaded therapeutic metal ions—in terms of obtaining constant therapeutic amount release of the ion over a period of time—have been very limited [18]. Amorphous peroxititanates (APT) might also be used to bind a variety of metal compounds with high-affinity forming complexes to control the delivery of metal-based drugs to the target tissue avoiding systemic toxicity, or to capture metal ions from body tissues [33–37]. Wataha et al .…”

Titanates and Titanate-Metal Compounds in Biological Contexts

“…Several years later, in a more detailed study, [14] THP1 monocytes were exposed to APT-metal compounds, but using cytokine secretion (IL6, IL1β, and TNFα.) as a measure of cellular effect [3,13].…”

“…However, titanate-metal compounds have emerged as a promising new class of antimicrobials against oral and skin bacterial infections. Titanate particles bind and sequester a variety of metals with high affinity, thus would be able to deliver metals to a site of infection with less systemic toxicity [14]. To assess the utility of metal titanate compounds against bacteria, studies first focused on the effects of native titanates and metal ions alone, then investigated the ability of titanate-metal compounds to inhibit bacterial growth.…”

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

“…In vitro tests with the noble metal-exchanged titanates indicate suppression of the growth of cancer and bacterial cells by an unknown mechanism. 8,9 Historically, sodium titanates have been produced using both sol-gel and hydrothermal synthetic techniques resulting in fine powders with particle sizes ranging from a few to several hundred microns. 4,5,10,11 More recently, synthetic methods have been reported that produced nanosize titanium dioxide, metal-doped titanium oxides, and a variety of other metal titanates.…”