l-Histidine-based organoclays for the storage and release of therapeutic nitric oxide

Abstract

Despite its toxicity, in low concentrations, nitric oxide (NO) is a small endogenous molecule with a particularly important role in the regulation of several biochemical pathways of the human body. The potential of L-histidine-modified clays (organoclays) for storage and therapeutic release of nitric oxide was assessed. Materials were characterized by powder X-ray diffraction, TG-DSC, IR spectroscopy, and nitrogen adsorption at −196 °C. The NO storage and release kinetics was studied both in the gas and liquid phases. For some materials, improvement was observed for both the released amounts and the release profile for the organoclays in relation to the respective raw clays. Assays with HeLa cells indicated that the materials have low cytotoxicity.