A bioactive glass material for the delivery of bone morphogenetic proteins: Synthesis by the solution sol-gel method, physical and chemical analyses, and in vitro testing

Although work of other investigators to date has provided much insight into the mechanism of bone repair using bone morphogenetic proteins (BMPs), the most fundamental clinical questions have remained unanswered; i.e., whether the BMPs can be placed in vivo in such a way as to force the initiation of bone regeneration and whether the regeneration response can be restricted to the desired location only. In this way, the choice of a suitable substrate for their delivery is central to the BMP repair methodology.;In this research, highly homogeneous bioactive glasses outside of the normally accepted bioactivity composition range were synthesized by the solution sol-gel technique. They were subsequently assessed for bioactivity in vitro and their ion exchange with a simulated body fluid was measured over a 7-day period. Their immersion in the fluid resulted in rapid precipitation of fine-grained hydroxyapatite crystals, as observed by SEM and FT-IR techniques. The experimental glasses were also tested for cellular compatibility by culturing osteoblast cells on the surface of pressed discs of the material. Here, the glass was shown to Provide a suitable substrate for cell growth and proliferation. Altogether, these findings suggest that this type glass may serve as a suitable bone grafting material and delivery substrate for BMPs in the repair of osseous defects.