Facile Synthesis of TiO 2 -SiO 2 -P 2 O 5 /CaO/ZnO with a Core-Shell Structure for Bone Implantation.

A facile synthesis method was developed to synthesize TiO 2 -SiO 2 -P 2 O 5 /CaO or TiO 2 -SiO 2 -P 2 O 5 /ZnO with a core-shell structure. The carboxylic cation exchanger Tokem-250 has a high selectivity for Ca 2+ /Zn 2+ ions and was used in this study. The framework of the material in the shell was TiO 2 -SiO 2 -P 2 O 5 , and the inner part was filled with CaO (sample TiO 2 -SiO 2 /CaO) or ZnO (sample TiO 2 -SiO 2 -P 2 O 5 /ZnO). A stepwise heat treatment (drying in a drying oven at 60 °C for 30 min, then annealing in a muffle furnace for 30 min at 150, 250, and 350 °C, at 600 °C for 6 h, and at 800 °C for 1 h) was needed to obtain a homogeneous material. The poly(vinyl alcohol) was used as a binding additive. The obtained composites were characterized by a regular structure and highly developed surface. The samples exhibit bioactive properties in the simulated body fluid (SBF) solution, since the surface contains active centers (Si 4+ , Ti 4+ ) which contribute to mineralization and precipitation of the calcium-phosphate compounds on the surface from biological media. The TiO 2 -SiO 2 -P 2 O 5 /CaO-PVA samples did not exceed acceptable hemolysis levels for medical materials.