Composites based on silicate bioactive glasses and silver iodide microcrystals for tissue engineering applications

•Silver iodide was introduced via sol-gel method into bioactive glasses as silver source.•After immersion in simulated body fluid appears the apatite layer without silver component (such as AgCl).•Presence of Ag0 metallic species in the glass structure affects the in vitro bioactivity and influenced the cell viability. AgI microcrystals are used as Ag nanoparticles’ source to avoid the transformation of silver into AgCl, whose presence can affect the materials’ biocompatibility. The AgI microcrystals are obtain by using solvothermal crystallization and then they are embedded into bioactive glass matrices using a sol-gel method. The influence of AgI concentration on the structural, morphological, bioactive and biocompatible properties of the composites is carefully analyzed. By using the above-mentioned approach, all the obtained samples are AgCl free. Furthermore, the sample with 0.1 mol% AgI shows the signature of mobile I− and Ag° metallic species that negatively affect the in vitro bioactivity. It is also demonstrated that the presence of Ag° metallic species restrained the keratinocytes cells viability. The composites with AgNPs and Ag2O species exhibited excellent bioactivity and good cell proliferation rate. A moderate antibacterial effect against Pseudomonas aeruginosa was also evidenced in the case of the composites with AgNPs content. [Display omitted]