Porous collagen-apatite nanocomposite foams as bone regeneration scaffolds.

We have created a porous bioresorbable nanocomposite bone scaffold that chemically, structurally and mechanically matched natural bone so that it could be recognized and remodeled by natural bone. Containing collagen fibers and synthetic apatite nanocrystals, our scaffold has high strength for supporting the surrounding tissue. The foam-like scaffold has a similar microstructure as trabecular bone, with nanometer-sized and micron-sized pores. The apatitic phase of the scaffold exhibited similar chemical composition, crystalline phase and grain size as the trabecular bone apatite. The nanocomposite scaffold demonstrated excellent bioactivity for promoting cell attachment and proliferation. It was osteoconductive and successfully healed a non-union fracture in rat femur as well as a critical-sized defect in pig tibia.