Poly (ε-caprolactone)/layered double hydroxide microspheres-aggregated nanocomposite scaffold for osteogenic differentiation of mesenchymal stem cell

In this study, Three-dimensional porous scaffolds made of Mg/Al-layered double hydroxide (LDH)/polycaprolactone (PCL) nanocomposites with different LDH contents have been prepared for bone tissue engineering applications. The microspheres-aggregated nanocomposite scaffolds were fabricated by freeze-drying and particulate leaching methods. The size of the microspheres ranges from 13 μm to 58 μm, in which the minimum microsphere size was achieved in the PCL scaffold with 0.1 wt% LDH. The hydrophilicity of the scaffolds was improved by the incorporation of LDH nanoparticles as demonstrated by the water contact angle measurement. The results of the mineralization study showed that the presence of Mg2+ ions could reduce the rate of apatite formation and calcium deposition in simulated body fluid (SBF). Furthermore, compared to the pure one, the nanocomposite scaffolds demonstrated better ability in protein adsorption and superior mechanical properties. The PCL/LDH scaffold can better support the growth and proliferation of rat bone marrow mesenchymal stem cells (rMSCs). Also, the results of the alkaline phosphatase activity assay determined that the addition of LDH nanoparticle into the PCL matrix could enhance the osteogenic differentiation of rMSCs. Altogether, our findings suggested that PCL/LDH (0.1−10 wt%) microsphere-aggregated scaffold may be a suitable candidate for the design of 3D scaffolds in bone tissue engineering application.