Aims and Objective: Clinoptilolite is one of the natural zeolites. Clinoptilolite particles
have a high surface area, negative surface charge, cation adsorption and exchange capacities.
Barium sulfate (BaSO4) and bismuth subnitrate (Bi5H9N4O22) suspensions have been used for
upper and lower gastrointestinal imaging but Ba2+ and Bi3+ ions are toxic. In the present study, the
feasibility of the application of Ba2+- and Bi3+-loaded clinoptilolite micro- and nano-particles in
medical imaging was investigated.
Materials and Methods: Nanoparticles and microparticles of natural clinoptilolite were loaded
with Ba2+ and Bi3+ ions. Radiopacities of loaded particles were measured and compared with those
of BaSO4 and Bi5H9N4O22.
Results: Ba2+- and Bi3+-loaded clinoptilolite nanoparticles and microparticles showed more intense X-ray
opacities than BaSO4 and Bi5H9N4O22 with equimolar concentrations. Moreover, Ba2+- and Bi3+-loaded
clinoptilolite nanoparticles more intensely absorbed X-ray than respective loaded microparticles.
Conclusion: The present study proposes Ba2+- and Bi3+-loaded clinoptilolite nanoparticles and
microparticles as new, safe, efficient, and inexpensive contrast agents.