Engineering the surface functionality of 45S5 bioactive glass-based scaffolds by the heterogeneous nucleation and growth of silver particles

An emerging topic in the field of biomaterials is the incorporation of silver ions, metallic silver or silver oxides into bioactive glasses to impart novel functionalities. In this work, a new approach of surface functionalization of 45S5 bioactive glass (BG) is introduced. In contrast to more common methods, which are based on the inclusion of silver during the sol–gel synthesis of BG, our method allows the surface functionalization of BG powders and BG scaffolds after their preparation. Hereby, we demonstrate the transferability of a previously reported approach on the wet chemical synthesis of cup-like and dendritic silver patches first from colloidal silica particles to BG particles and further to macroscopic highly porous BG scaffolds which were prepared by the sacrificial foam replica technique. The time-dependent silver releases of BG scaffolds with different silver loadings into simulated body fluid (SBF) were measured. Further studies were addressed to investigate the bioactivity of BG scaffolds before and after the silver coating procedure. It was found the silver deposition on 3D BG scaffolds did not affect the formation of crystalline hydroxyapatite during immersion into simulated body fluid.