Self-assembling peptide and nHA/CTS composite scaffolds promote bone regeneration through increasing seed cell adhesion

Porous scaffolds fabricated with nano-hydroxyapatite (nHA) and chitosan (CTS), are widely used in bone tissue engineering (BTE). However, cell adhesion is relatively poor in nHA/CTS scaffolds, which also do not provide an ideal three-dimensional environment for seed cells. These deficiencies limit the applicability of these BTE scaffolds to repair bone defects. To address these challenges, we designed a composite scaffold that combines nHA/CTS with self-assembling peptide (SAP), a material which is similar to the extracellular matrix. We found that SAP/nHA/CTS scaffolds both increased the adhesion of bone mesenchymal stem cells (BMSCs) and enhanced the mechanical properties of the scaffold. This composite scaffold was then used to repair a femoral condylar bone defect in a mouse model. Healing and mineralization was demonstrated after 12 weeks using H&E staining, microcomputerized tomography, and bone mineral density tests. To our knowledge, this is the first report that SAP/nHA/CTS scaffolds can increase cell adhesion and promote the reconstruction of femoral condylar bone defects. Moreover, this study indicates that BTE using a SAP/nHA/CTS scaffold may be a novel prospective strategy for healing extensive bone defects.