Synthesis of 3D porous ceramic scaffolds obtained by the sol-gel method with surface morphology modified by hollow spheres for bone tissue engineering applications

摘要

? 2022 The AuthorsIn the present work, we modified the surface morphology of 3D porous ceramic scaffolds by incorporating strontium phosphate (SrP) hollow nano-/microspheres with potential application as delivery system for the local release of therapeutic substances. SrP hollow spheres were synthesized by a template-free hydrothermal method. The influence of the reaction temperature, time and concentration of reactants on precipitates' morphology and size were investigated. To obtain a larger number of open hollow spheres, a new methodology was developed consisting of applying a second hydrothermal treatment to spheres by heating them at 120 °C for 24 h. The X-ray diffraction (XRD) analysis indicated that spheres consisted of a main magnesium-substituted strontium phosphate phase ((Sr0.86Mg0.14)3(PO4)2). The scanning electron microscopy (SEM) micrographs confirmed that spheres had hollow interiors (～350 nm size) and an average diameter of 850 nm. Spheres had a specific surface area of 30.5 m2/g, a mesoporous shell with an average pore size of 3.8 nm, and a pore volume of 0.14 cm3/g. These characteristics make them promising candidates for drug, cell and protein delivery. For the attachment of spheres to scaffolds’ surface, ceramic structures were immersed in an ethanol solution containing 0.1 g of hollow spheres and kept at 37 °C for 4 h. The scaffolds with incorporated spheres were bioactive after being immersed in simulated body fluid (SBF) for 7 days and spheres were still adhered to their surface after 14 days.