Calcium phosphate biomaterials modified with Mg2+ or Mn2+ ions: Structural, chemical, and biological characterization

This study presents a method for the synthesis of calcium phosphate (CaPs) ceramic materials and its derivative cements (CPCs). The ceramics were prepared by a wet precipitation method from calcium phosphate salts, with substitution of Mg 2+ and Mn 2+ ions. In addition, the cements were formulated using phosphoric acid and citric acid as reactants. The ceramic powders were characterized by determining the calcium/phosphorus (Ca/P) ratio, specific surface area (SSA) as well as porosity. Moreover, both ceramic powders and synthesized cements were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), pore size distribution, scanning electron microscopy (SEM) for surface morphology and hardness tests. The effects of the created biomaterials on the viability of human cell lines were evaluated on cancer (neuroblastoma SHSY5Y, A172 glioblastoma) and non-cancerous (osteoblast hFOB 1.19, BJ fibroblasts) models. Glioblastoma A172 cells were not susceptible to proposed materials. The viability of the cells did not decrease more than 24%. The neuroblastoma and fibroblastic cells were more susceptible to cements, resulting from the Ca2+ concentration in the extracellular space. The osteoblastic cells expressed higher mortality in response to proposed Mg and Mn cements, however their function was not affected. The results indicate that the ionically substituted ceramic powders exhibited a reduced Ca/P ratio. All synthesized cements demonstrated well-defined structures with distinct sharp edges. These findings highlight the potential of the proposed synthesis methods to produce calcium phosphate ceramics and cements with tailored physicochemical properties, making them promising candidates for bone tissue engineering applications.