Fabrication of a highly ordered hierarchically designed porous nanocomposite via indirect 3D printing: Mechanical properties and in vitro cell responses

Design and development of biodegradable scaffolds with highly uniform and controlled internal structure that stimulate tissue regeneration are the focus of many studies. The aim of this work is to apply a modified three-dimensional (3D) printing process to fabricate polymer-matrix composites with controlled internal architecture. Computationally-designed plaster molds with various pore sizes in the range of 300-800 mu m were prepared by employing 3D printing of a water-based binder. The molds were converted to e-polycaprolactone (PCL) and PCL/bioactive glass (BG) composite scaffolds by solvent casting and freeze drying methods. Optical and electron microscopy studies revealed that the pore structure was retained without shape distortion of the scaffolds. The wall structure of the pores was composed of a homogeneous fibril interconnected porous surface. The mechanical properties of the scaffolds were evaluated by uniaxial compression and nano-indentation tests. In vitro cell studies by MC3T3-E1 mouse preosteoblast cells showed that the prepared 3D scaffolds supported cell adhesion, tissue growth and cell differentiation. The effect of pore geometry and bioactive glass particles on the mechanical properties and tissue growth were evaluated. The results of mechanical examinations and in vitro cell responses determined the potential of the process for the fabrication of non-load bearing 3D scaffolds. (C) 2015 Elsevier Ltd. All rights reserved.