The evaluation of the osteopromoting capabilities of composites based on biopolymers and gold/silver nanoparticles doped bioactive glasses on an experimental rat bone defect

The most important concept behind using bone scaffolds is the biocompatibility of the material to avoid a local inflammatory response and must have the following properties: osteoinduction, osteoconductivity, angiogenesis, and mechanical support for cell growth. Gold nanoparticles/gold and silver nanoparticles -containing bioactive glasses in biopolymer composites have been used to enhance bone regeneration. These composites were tested in vitro on fibroblast and osteoblast cell lines using MTT tests, immunofluorescence, scanning electron microscopy analysis, and in vivo in an experimental bone defect in Sprague-Dawley rats. Both composites promoted adequate biological effects on human fibroblastic BJ (CRL 2522TM) cell lines and human osteoblastic cells isolated from the human patella in terms of cell proliferation, morphology, migration, and attachment. Most importantly, they did not cause cellular apoptosis and necrosis. According to the histological and immunohistochemical results, both composites were osteoinductive and promoted new bone formation at 60 d. Evidence from this study suggests that the small amount of silver content does not influence negatively the in vitro or in vivo results. In addition, we obtained accurate results proving that the existence of apatite layer and proteins on the surface of the recovered composite, supports the validity of in vitro bioactivity research.