Effect of polycaprolactone impregnation on the properties of calcium silicate scaffolds fabricated by 3D printing

Calcium silicate (CS) is a suitable substrate for bone tissue engineering because it can provide bioactive ions like Si4+ and Ca2+ to promote bone regeneration. However, the rapid degradation of CS leads to pH problems and does not match the rate of osteogenesis. The 3D printed CS scaffolds were immersed in Polycaprolactone (PCL) solution to obtain PCL-coated scaffolds with improved mechanical and biological properties. Finite element method (FEM) analysis found that PCL impregnation has the effect of stress shielding and defect healing, effectively improving the mechanical properties of CS porous scaffolds. The degradation rate of PCL-coated scaffolds was significantly slowed down in Tris buffer. After 4 weeks of degradation, the compressive strength of PCL-coated scaffolds remained at 23.34 MPa, maintaining reliable mechanical properties. PCL coating significantly reduced the degradation rate of CS scaffolds, and the pH value and Si ion concentration of Dulbecco's modified Eagle's medium (DMEM) soaked by PCL-coated scaffolds were more favorable for cell survival. The results show that PCL-coated scaffolds enhance cell proliferation and osteogenic differentiation, demonstrating the potential applicability of bone tissue engineering applications