Apatite-wollastonite glass-ceramics containing B2O3 and Na2O: Potential bioactive material for tissue protection during radiation therapy procedures

Abstract

In this study, an attempt to expand available data and functionality of apatite-wollastonite glass ceramics (AW GCs) in medical therapy and bone engineering by estimating and analysing the physical, structural, fast neutron and gamma interaction properties of B2O and Na2O doped AW GCs is presented. The pristine (AW) and (20 wt% B2O3 and 30 wt% Na2O) doped AW GC (AW-B20-N30) samples were prepared using the cold isostatic press method. The samples were subject of structural and physical characterisation through experimental procedures, while their radiation interaction parameters were obtained following standard theoretical models. Samples’ densities were calculated as 2.917 and 2.613 g/cm3, while the Vickers hardness was 553 and 518 HV for AW and AW-B20-N3, respectively. The structure of the samples revealed that Na2O formed the brianite phase inserted in the apatite structure. The mass and linear attenuation coefficients fluctuated within the ranges, 0.0232-13.6853 cm2/g and 0.0676-39.92 cm-1 for AW and 0.021-8.313 cm2/g and 0.055-21.7223 cm-1 for AW-B20-N30, respectively. The half- and tent-value layers increased from about 0.02 to 10.25 cm and 0.06 to 34.05 cm for AW; for AW-B20-N30, the increase is from 0.032 to 12.61 cm and 0.11 to 41.88 cm, respectively. AW was more effective for shielding photons and fast neutrons, and had lower gamma buildup factors compared to AW-B20- N30. The study showed doping AW with B2O and Na2O could be optimised to get equivalent bone material in radiation studies. The AW GCs also showed better shielding effectiveness compared to some traditional shields and could therefore be applied for shielding tissues outside the target volume in radiation therapy