Gadolinium-loaded LTL nanosized zeolite for efficient oxygen delivery and magnetic resonance imaging

The key challenges in finding efficient gas carriers for biomedical applications are related to the kinetics of gas adsorption/desorption of non-toxic materials over appropriate time intervals, specifically targeting the affected area. Herein, we report the preparation of nanosized gadolinium (Gd-LTL) zeolite crystals with a diameter of 10-15 nm for oxygen delivery combined with a magnetic resonance imaging (MRI) study. The partial ion-exchange of potassium (K) extra framework cations used for the synthesis of nanosized K-LTL zeolite with paramagnetic gadolinium (Gd, 1.53 wt%) changed its adsorption capacity for O-2 considerably. The nanosized Gd-LTL zeolite retained high colloidal stability and remarkable crystallinity, and no leaching of Gd ions was observed. In addition, the in vitro toxicity study performed in human glioblastoma-derived cell lines revealed that nanosized K-LTL and Gd-LTL nanosized zeolites showed no toxicity, even at high concentrations. This study provides promising guidelines regarding the design of smart biocompatible nanosized zeolites coupling gas-delivery and MRI properties.