Synthesis and characterization of phosphate glass microspheres for radiotherapy applications

Glass microspheres containing the radioisotope 32P, a β− particle emitter, and half-life of 14.3 days, can be easily introduced in specific human organs such as liver, pancreas, and uterus to kill cancer cells. In the present work phosphate glass microspheres were produced with different compositions and particle size distribution in the range of 20– 30 μm. Two different thermal processes were used to spherodize glass particles originally with irregular shapes. Samples were characterized by X-rays diffraction to check the amorphous structure, energy dispersive X-rays fluorescence spectroscopy to determine the final glass composition, and Fourier transformed infrared spectroscopy to determine the structural groups in the glass structure. The dissolution rate of glass samples in water was determined at 90 °C, and in simulated body fluid (SBF) at 37 °C. Glasses with dissolution rates close to 10−5 g/(cm2 day) were obtained, which make them suitable for the present application. Scanning electron microscopy was used to evaluate the shape of the microspheres before and after the dissolution tests. The cytotoxicity tests showed that these microspheres can be used for biological applications.