Design and preparation of μ-bimodal porous scaffold for tissue engineering

The aim of this study was to prepare poly-epsilon-caprolactone (PCL) foams, with a well-defined micrometric and bimodal open-pore dimension distribution, suitable as scaffolds for tissue engineering. The porous network pathway was designed without using toxic agents by combining gas foaming (GF) and selective polymer extraction techniques. PCL was melt-mixed with thermoplastic gelatin (TG) in concentrations ranging from 40 to 60 wt %, to achieve a cocontinuous blend morphology. The blends were subsequently gas foamed by using N-2-CO2 mixtures, with N-2 amount ranging from 0 to 80 vol %. Foaming temperature was changed from 38 to 110 degrees C and different pressure drop rates were used. After foaming, TG was removed by soaking in H2O. The effect of blend compositions and GF process parameters on foam morphologies was investigated. Results showed that different combinations of TG weight ratios and GF parameters allowed the modulation of macroporosity fraction, microporosity dimension, and degree of interconnection. By optimizing the process parameters it was possible to tailor the morphologies of highly interconnected PCL scaffolds for tissue engineering. (c) 2007 Wiley Periodicals, Inc.