Fabrication of poly(ε-caprolactone) tissue engineering scaffolds with fibrillated and interconnected pores utilizing microcellular injection molding and polymer leaching

Abstract

Three-dimensional (3D) fibrillated interconnected porous poly(ε-caprolactone) (PCL) scaffolds with desirable pore sizes and porosities were prepared by blending PCL with water-soluble poly(ethylene oxide) (PEO) as a sacrificial material, followed by microcellular injection molding and polymer leaching techniques. Immiscibility, morphology, mechanical properties, hydrophilicity, and biocompatibility of the scaffolds were investigated. Differential scanning calorimetry (DSC) and phase morphology indicated that PCL and PEO were immiscible. The incorporation of PEO not only facilitated the processing of PCL by decreasing its viscosity, it also improved the porosity and interconnectivity of the post-leached PCL scaffolds. It was found that the variety of pore diameters improved and the porosity increased up to 89.5% for the 50% PCL/50% PEO blend by volume (50% PCL). The compression modulus of the porous PCL scaffold decreased from 68.2 MPa for neat PCL to 46.7 MPa for 50% PCL due to an increase in porosity. 3T3 fibroblast cell culture was performed to confirm the biocompatibility and cell viability of the scaffolds. Cells were found to proliferate the best on the 50% PCL scaffolds, as compared to the other three scaffolds. In light of the resulting elongated and spindle-shaped pore structures as well as the biocompatibility and cell viability, this method offers an alternative means for the scalable fabrication of tissue engineering scaffolds.