Degradable smart composite foams for bone regeneration

Degradable scaffolds with high porosity, certain mechanical and shape memory properties and biocompatibility are ideal materials in the field of bone tissue engineering for minimally invasive surgical implantation methods. In this study, we prepared porous scaffolds using hydrophilic polyethylene glycol and degradable polycaprolactone as raw materials and calcium citrate/amorphous calcium phosphate as hybrid particles, via sequential gas foaming, salt leaching and freeze drying methods. The fabricated bone scaffold exhibited adjustable mechanical properties and pore structure , with high shape fixation (>94.5%) and shape recovery (>87%) in thermal cycling and excellent shape memory properties under simulated body fluid immersion near body temperature. Moreover, in cell proliferation and live/dead cell activity assay experiments, the scaffolds promoted the proliferation of mesenchymal stem cells (MSCs). Immunofluorescence staining assay experiments further showed that the scaffolds had strong expressions of human type Ⅰ collagen (Col I) and alkaline phosphatase (ALP) in bone matrix. The material is expected to be a potential alternative material for bone tissue engineering.