Prussian Blue Nanoparticles Confined in Chitosan for In Vivo Cesium Ion Removal

The development of efficient and biocompatible sorbent nanomaterials for cesium removal is critical for environmental and biomedical decontamination. Here, hybrid composites based on ultra-small Prussian blue or Zn Prussian blue-type nanoparticles confined within porous chitosan beads are proposed for Cs⁺ extraction. Nanoparticle confinement ensures homogeneous dispersion and improved accessibility of ion-exchange sites, while preserving the porous polymeric network, as confirmed by physicochemical characterization. Cs⁺ adsorption was investigated under neutral and acidic conditions (pH 7.2 and 1.2), at concentrations of 0-9 mmol/L and contact times of 0-50 h, showing efficient uptake and favorable kinetics, with confirmed stability in simulated gastric fluid. In vivo performance was assessed in a mouse model of cesium contamination (70 mg Cs⁺/kg). Treatment with nanocomposites (225 mg/kg) was compared to bulk Prussian blue (75 mg/kg), revealing enhanced detoxification efficiency. Histological analysis of liver, spleen, and kidney tissues showed no detectable structural damage, consistent with unchanged systemic biomarkers. Overall, the proposed chitosan-confined Prussian blue-type nanocomposites combine high Cs⁺ removal efficiency, kinetic accessibility, and in vivo safety, highlighting their potential for decorporation applications.