Clay nanofiller enhances and stabilises a new injectable human bone extracellular matrix scaffold for skeletal regeneration

Critical bone defects and fractures are typically treated using autologous bone grafts, which are limited by volume of bone that can be harvested, or allogeneic or synthetic bone grafts that lack osteoinductive properties. Human bone extracellular matrix (hbECM) is widely available and offers the potential to be used as a native material to synthesize functional injectable hydrogel systems. However, hbECM lacks the mechanical stability required for injectability and bone growth. We have explored the use of Laponite® (LAP) nanoclay and sodium polyacrylate to augment the mechanical and biological properties of hbECM gel. We demonstrated that the inclusion of LAP into ECM improved the physicochemical properties of hbECM and consequently promoted cell responses confirming that the nanoclay platelet-to-platelet interaction is key to sustain hbECM functionality. This novel hbECM detailed offers significant clinical promise for bone repair.