Gadolinium zeolite as an oral contrast agent for magnetic resonance imaging

Abstract

The purpose of this study was to evaluate efficacy and safety of a gadolinium (Gd) zeolite suspension as an oral MRI contrast agent. Serial dilutions of GADO-LITE Oral Suspension 1,2-300 micrograms of Gd(III)/mL) were prepared. MRI (T1 and T2 weighted) of standards and dogs (precontrast and postcontrast) were performed. Toxicity and Gd absorption were also assessed. Subsequently, 30 normal male adult volunteers were divided into six groups of five subjects each. Gd zeolite po suspension was administered before and after MRI in volumes and concentrations ranging from 250 to 1500 mL; 6 to 60 micrograms of Gd+3/mL. The images were rated (efficacy score) by a blinded reader. Vital signs, blood chemistries and urinalysis were recorded. Gadolite Oral Suspension produced excellent enhancement of the dog gastrointestinal (GI) tract. No toxicity or absorption of Gd was observed in dogs receiving doses up to 4 times the anticipated human dose daily for 14 consecutive days. In clinical trials, Gd zeolite significantly improved the efficacy scores for all groups and all pulsing sequences (all P values < .05). Efficacy scores and signal intensities generally increased with concentration and volume. No Gd was detected in blood or urine specimens. No significant adverse events were reported. Gd zeolite is a promising contrast medium for enhancement of the GI tract in MRI.

Use of pineapple juice with gadopentetate dimeglumine as a negative oral contrast for magnetic resonance cholangiopancreatography: a multicentric study

“…The gadopentetate dimeglumine was chosen due to its safety for oral administration, which has been demonstrated [32][33][34][35].…”

Zeolite 4A, a Synthetic Silicate, Suppresses Melanogenesis through the Degradation of Microphthalmia-Associated Transcription Factor by Extracellular Signal-Regulated Kinase Activation in B16F10 Melanoma Cells

“…Zeolite is known that silicates and aluminosilicates possess biological activity and also are nontoxic agents. They have been studied in safe oral contrast agent for human magnetic imaging work 11) and in the context of animal feeds.…”

“…Zeolite is known that silicates and aluminosilicates possess biological activity and also are nontoxic agents. They have been studied in safe oral contrast agent for human magnetic imaging work 11) and in the context of animal feeds. 12) Recently, zeolite was found to be a new adjuvant in anticancer therapy, 10) and demonstrated to decreases TiO 2 -photosensitized reactive oxygen species (ROS) generation in cultured human skin fibroblasts.…”

“…Zeolite is known that silicates and aluminosilicates possess biological activity and also are nontoxic agents. They have been studied in safe oral contrast agent for human magnetic imaging work 11) and in the context of animal feeds.12) Recently, zeolite was found to be a new adjuvant in anticancer therapy, 10) and demonstrated to decreases TiO 2 -photosensitized reactive oxygen species (ROS) generation in cultured human skin fibroblasts. 10,13) In the present study, we demonstrate that zeolite 4A inhibits MITF-mediated tyrosinase expression and melanin synthesis via increasing extracellular signal-regulated kinase (ERK) activity in B16F10 melanoma cells.…”

Supramolecular photochemistry in zeolites: From catalysts to sunscreens

“…Zeolites have already found some limited use in the medical sciences as MRI contrast agents and anticoagulant-releasing materials for medical implants [146,147]. Hopefully, the preliminary investigations of encapsulated sunscreens described here will provide yet another avenue of exploration for zeolite-based materials.…”