Electrophoretic deposition of spray-dried Sr-containing mesoporous bioactive glass spheres on glass–ceramic scaffolds for bone tissue regeneration

The development of strong and bioactive scaffolds with a trabecular architecture mimicking that of cancellous bone is one of the major and still partially unmet challenges of modern biomaterials science and regenerative medicine. In this work, we exploited the electrophoretic process to deposit highly bioactive particles of mesoporous glass on the struts of a mechanically strong but almost inert glass–ceramic scaffold produced by the sponge replica method. A SiO2–CaO–SrO mesoporous glass was innovatively synthesized by aerosol-assisted spray drying in order to obtain spherical particles with high control over shape and morphology. The glass microspheres underwent morphological, chemical and textural characterizations, and the release kinetics of strontium—known for its ability to stimulate new bone formation in osteoporotic bone—were assessed upon immersion in simulated body fluid. Sr-containing mesoporous glass particles electrophoretically deposited on the scaffold walls retained a fast apatite-forming ability and formed a highly bioactive coating on the macroporous substrate without occluding the pores. The meso-macroporous hierarchical constructs produced in this research could be proposed as bioactive and mechanically strong implants for potential applications in bone tissue engineering.