Generation of biocompatible PCL foams by supercritical foaming

In this work, polycaprolactone (PCL) foams were generated by a supercritical CO2 (SC-CO2) assisted process. These foams can find application in tissue engineering as scaffolds, which require specific biological and morphological properties. SC-CO2 foaming process was carried out under different pressure and temperature conditions, in order to study the influence of these operating parameters on the final samples morphology. These polymeric foams were then analyzed by scanning electron microscope (FE-SEM) in order to observe their internal structure. The performed analyses showed the influence of pressure and temperature on the external shape and on the morphology of these polymeric foams, in particular on the pore size. Pressures of 100, 150, 200 and 250 bar and temperatures of 40 and 60°C were tested as operating variables. The PCL foams obtained at 40°C and 200 bar presented the lowest value of the average pores diameter (i.e., 85 ± 24 μm); this value was about 7 times lower than that of the foams produced operating at 40°C and 100 bar (622 ± 62 μm). These results confirmed the high versatility of the SC-CO2 foaming that allowed to generate PCL foams with tunable morphological characteristics.