Synthesis, chemical characterization and radiological response of Ho and HoZr bioglass seeds

Abstract

This work aims to study the synthesis and characterization of Ho and HoZr bioglass seeds, in addition to radiological response with the contrast agent Zr incorporated. The cylindrical seeds, identified also as [Si:Ca:Ho] and [Si:Ca:Ho:Zr], were synthesized by the sol–gel method and coated with acrylic resin and polyvinyl alcohol membrane . Analysis of the mass attenuation coefficients of Ho and Zr according to the medical X-ray spectrum was performed. The synthesized bioglasses were characterized by quantitatively and qualitatively evaluating the main elemental composition. The following characterization techniques were performed: UV–Vis spectrometry, energy-dispersive X-ray fluorescence (EDS) and X-ray fluorescence with CdTe detector and americium excitation source (Am-241). As results, seeds were synthesized and coated within the two established dimensions of 0.35 ± 0.05 and 0.65 ± 0.05 mm diameters and 1.50 ± 0.10 and 1.57 ± 0.05 mm lengths. The Ho composition was 30.7 % and Zr 22.2 % on [Si:Ca:Ho:Zr] seeds. The mass attenuation coefficient of zirconium showed to be eightfold superior to the holmium within the medical diagnosis spectra. Radiological response of [Si:Ca:Ho:Zr] seeds showed 20 % higher contrast compared to [Si:Ca:Ho], within a background equivalent to breast glandular tissue, resulting in an appropriate radiological visibility of [Si:Ca:Ho:Zr]. As conclusion, the characterization methods have identified their elemental composition. Insertion of Zr in the synthesis has increased the radiological contrast, allowing implant’s monitoring by conventional X-ray or mammogram.