Selenium-Enriched Brushite: A Novel Biomaterial for Potential Use in Bone Tissue Engineering.

In this study, a novel biomaterial, i.e., brushite containing 0.67 wt% of selenium (Se-Bru) was synthesized via a wet precipitation method. Pure, unsubstituted brushite (Bru) was synthesized via the same method and used as a reference material. Different techniques of instrumental analysis were applied to investigate and compare physicochemical properties of both materials. Fourier-Transform Infrared Spectroscopy confirmed the chemical identity of both materials. Scanning Electron Microscopy (SEM) was used to study the morphology and indicated that both samples (Bru and Se-Bru) consisted of plate-like microcrystals. Powder X-ray Diffraction (PXRD) showed that Bru, as well as Se-Bru were crystallographically homogenous. What is more, the data obtained from PXRD studies revealed that the substitution of selenite ions into the crystal structure of the material had clearly affected its lattice parameters. The incorporation of selenium was also confirmed by solid-state ¹H→31P CP MAS kinetics experiments. Additionally, studies on the release kinetics of the elements forming Se-Bru and preliminary cytotoxicity tests were conducted. This preliminary research will favor a better understanding of ionic substitution in calcium phosphates and may be a starting point for the development of selenium-doped brushite cements for potential use in bone tissue impairments treatment.