FIBRILLATED AND HIGHLY INTERCONNECTED POROUS PCL SCAFFOLDS BY COMBINATION OF SUPERCRITICAL FOAMING AND LEACHING

Highly porous and interconnected 3D structures are crucial elements for tissue engineering scaffolds since they can support the mass transport of cell nutrients and waste. Supercritical foaming technology is an environmentally-friendly and solvent-free way of manufacturing porous scaffolds. In this research, highly porous, interconnected poly(ε-caprolactone) (PCL) scaffolds combined with supercritical carbon dioxide (SCCO2) foaming and a polymer leaching process were fabricated by blending PCL with water-soluble poly (ethylene oxide) (PEO) as a sacrificial material. The effects of phase morphology of PCL/PEO blend on foaming behavior and pore morphology were investigated. The incorporation of PEO not only facilitated the foaming of PCL by increasing its viscosity, but also improved the porosity and interconnectivity of the post-leached PCL scaffolds. The fibrillated porous scaffolds with open-pore content up to 91% were obtained after the leaching process because of two different cell-opening mechanisms. Cell-opening on surface of scaffolds is difficult in preparing porous materials. In the end, a novel method for improving surface porosity and producing the so-called outer and inner porous PCL scaffolds is described. The information gathered in this study may provide a theoretical basis for research into porous tissue engineering scaffolds.