2.2. Scaffold preparationPCL mats w

2.2. Scaffold preparation
PCL mats were die-punched into scaffolds 6 mm in diameter with thicknesses between 0.95 and 1.05 mm. As previously characterized through scanning electron microscopy and mercury porosimetry, these scaffolds had an average fiber diameter of 9.86 ± 0.56 μm and a porosity of 87% with an average pore size of 45 μm [11] and [12]. Prior to use, PCL scaffolds were sterilized with ethylene oxide gas for 14 h and aerated overnight to remove residual fumes. Scaffolds were pre-wetted by centrifuging through a graded series of ethanol from 100% to 70%, followed by three rinses in phosphate buffered saline (PBS), and incubated in cell culture medium overnight. In preparation for cell seeding, scaffolds were press-fitted into cassettes designed to confine the cell suspension and to be used in the flow perfusion bioreactor