Evaluation and Comparison of Antimicrobial Properties of Natural and Synthetic Zeolites Exchanged with Silver, Zinc, Copper and Nickel Ions

Zeolites are high-porous active crystalline biomaterials. Recently many studies have been done on their antibacterial properties especially on zeolites exchanged with metallic cations. In this paper, we investigate the effective factors on the antimicrobial activity of natural and synthetic zeolites exchanged with silver, zinc, copper nickel, and bromide cations. This study reviews the published articles on the antibacterial properties of the natural and synthetic pure zeolites as well as the ion exchange ones. The results of our investigation show that ion exchange zeolites exhibit a very good antibacterial effects even in comparison with other conventional antibacterial materials. The strongest antibacterial activity was reported in silver exchanged zeolites against Bacillus cereus and Escherichia coli with MIC of 16 μg/ml. According to the results reported derived from different articles, it can be concluded that zeolites with biocompatibility and high ion exchange capacity can be used as efficient antibacterial materials. Pure zeolites have antibacterial activity at high concentrations, whereas all synthetic and natural zeolites exchanged with metal cations investigated in this paper exhibit good antibacterial activity at very low concentrations generally due to sustained and prolong release of metal cations.