Comparison of X-Ray Attenuation Performance, Antimicrobial Properties, and Cytotoxicity of Silicone-Based Matrices Containing Bi2O3, PbO, or Bi2O3/PbO Nanoparticles.

Background: Application of the nanomaterials to preparing X-ray shields and successfully treating multiresistant microorganisms has attracted great attention in modern life.

Objective: This study aimed to prepare flexible silicone-based matrices containing Bi₂O₃, PbO, or Bi₂O₃/PbO nanoparticles and select a cost-effective, cytocompatible, and antibacterial/antifungal X-ray shield in clinical radiography.

Material and methods: In this experimental study, we prepared the nanoparticles by the modified biosynthesis method and fabricated the X-ray shields containing 20 wt% of the nanoparticles. The X-ray attenuation percentage and Half Value Layer (HVL) of the shields were investigated for the photon energies in the range of 40-100 kVp in clinical radiography. The antibacterial/antifungal activities of the shields were evaluated using a colony count method for the gram-negative (Escherichia coli), and gram-positive (Enterococcus faecalis) bacteria, and Candida albicans fungus. The shield toxicity was investigated on A549 cells.

Results: The highest X-ray attenuation percentage and the lowest HVL were obtained using the shield containing Bi₂O₃ nanoparticles. Although all shields displayed antimicrobial activity, the shield containing Bi₂O₃/PbO nanoparticles showed the most effective reduction in the colony counts. Both X-ray shields containing nano Bi₂O₃ and Bi₂O₃/PbO demonstrated high cytocompatibility on A549 cells at a concentration as high as 500 µg/ml. The shield with PbO nanoparticles was also cytocompatible at a concentration of 50 µg/ml.

Conclusion: The best X-ray attenuation performance is attributed to the silicone-based matrix with nano Bi₂O₃; however, the flexible shield with Bi₂O₃/PbO nanoparticles can be cost-effective and cytocompatible with the best antibacterial/antifungal properties.