Radially Porous Nanocomposite Scaffolds with Enhanced Capability for Guiding Bone Regeneration In Vivo

Abstract An ideal bone repair scaffold is expected to possess superior architectural characteristics to facilitate the adhesion, proliferation, and migration of bone‐repair‐related cells, while excluding nonosteogenic cells and fibrous tissues from interfering with normal bone regeneration. Unfortunately, such scaffold material has rarely been reported. Herein, nanocomposite scaffolds with a radially ordered porous structure are presented, manufactured using a modified directional freeze‐casting method, and are promising bone defect repair materials to satisfy this requirement. The prepared nanocomposite scaffolds consist of a natural bio‐macromolecule, chitosan, and bioactive hydroxyapatite nanoparticles derived from porcine cortical bone, demonstrating favorable biocompatibility and biological functions. Both in vitro cell studies and in vivo animal studies reveal the great superiority of the radially oriented porous structure of the scaffolds in guiding bone regeneration, while simultaneously preventing the invasion of surrounding nonosteogenic cells and fibrous tissue, compared to the axially oriented porous structure. This work indicates the distinctive potential of radially oriented porous scaffolds for repairing tabular and lacunar bone defects.