New iron-doped multilayer ceramic scaffold with noncontinuous bioactive behavior

Abstract New multilayer porous ceramic scaffolds, constituted by a core covered with external layers, are proposed as future bone tissue implants. The core with composition SiO2 - 25P2O5 – 68CaO–6Li2O (mol%) provided suitable compressive strength (0.9–1.6 MPa) to act as an initial support during bone tissue regeneration. The external layers with composition 29SiO2 - 3P2O5 - (68-x) CaO - xFe2O3 (mol%) (x = 0.3 and 1) (samples C/EL-1Fe and C/EL-3Fe, respectively) conferred a bioactive character to scaffolds. The surfaces of both samples showed apatite precipitates after coming into contact with simulated body fluid (SBF). Sample C/EL-1Fe exhibited noncontinuous bioactive behavior, with precipitates of apatite that precipitated and dissolved between days 1 and 28. Sample C/EL-3Fe showed precipitates after 8 days that remained until the end of the study time. This variation in material, achieved by modifying the amounts of iron in external layers, represents an important advance in the ability to control an implant's bioactivity in line with requirements of future applications.