Programmable, biodegradable composite scaffolds with variable pore morphology for minimal invasive bone repair

Tissue engineered biocompatible scaffolds could mimic the natural bone structure for cell adhesion and proliferation, however, patients suffer from large volume implantation. In this study, a porous composite biocompatible bone scaffold based on shape memory polymer materials (SMP) was developed from poly(ε-caprolactone) (PCL) diol, hexamethylene diisocyanate (HDI) and hydroxyapatite (HA). The prepared shape memory composite scaffold presented good pore connectivity, high porosity, good mechanical and biological properties. Additionally, after programming to a temporary shape, the scaffolds could recover to the initial shape, filling the site of bone defect. Moreover, HA improved the mechanical properties of scaffolds, promoted cell adhesion and influencing the shape recovering speed. During in vitro mineralization, HA could promote the formation and deposition of bone-like hydroxyapatite and accelerate the repair of damaged tissues, no inflammatory problem occurred after the in vivo implantations. These programmable scaffolds could be applied in minimal invasive bone repair.