Novel 3D porous multi-phase composite scaffolds based on PCL, thermoplastic zein and ha prepared via supercritical CO2 foaming for bone regeneration

The aim of this study was the design of novel biodegradable porous scaffolds for bone tissue engineering (bTE) via supercritical CO2 (scCO2) foaming process. The porous scaffolds were prepared from a poly(ε-caprolactone)-thermoplastic zein multi-phase blend w/o interdispersed hydroxyapatite particles (HA) and the porous structure achieved via the scCO2 foaming technology. The control of scaffolds porosity was obtained by modulating materials formulation and foaming temperature (TF). The scaffolds were subjected to morphological, micro-structural and biodegradation analyses, as well as in vitro biocompatibility tests. Results demonstrated that both HA concentration and TF significantly affected the micro-structural features of the scaffolds. In particular, scaffolds with porosity and pore size distribution, mechanical properties and biodegradability adequate for bTE were designed and produced by selecting a TF equal to 100 °C for all the compositions used. The biocompatibility of these scaffolds was assessed in vitro by using osteoblast-like MG63 and human mesenchymal stem cells (hMSCs).