Biodegradable porous scaffolds with or without bioactive molecules prepared by clean techniques attract an enormous interest for tissue engineering applications. Scaffolds work as structural support for both cell implantation and growth, favoring the regeneration or formation of new tissue. Scaffold requisites for tissue engineering applications include a proper material selection, which has to be biocompatible and biodegradable and with a good balance of mechanical properties, as well as control of the developed scaffold structure (highly porous and almost fully interconnected for cell penetration). Among the possible materials used for tissue engineering scaffold preparation synthetic biopolymers and particularly those based on poly(lactic acid) (PLA) have been increasingly used. There are several available methods to prepare porous scaffolds, each one leading to specifi c morphological characteristics in terms of porosity, open-pore content, pore size, and distribution. Among these, foaming of PLA-based materials by supercritical CO2 dissolution has recently found a great deal of interest, since it is a solvent-free and low temperature technique that has been demonstrated to allow a proper control of the scaffold structure by carefully regulating the foaming parameters. Beside these considerations addressed in this entry, it is shown that there is a clear trend toward the development and use of novel hybrid scaffolds based on biocompatible PLA-based foams prepared by solvent-free foaming techniques combined with bioactive micro- or nanometric-sized ceramic particles and natural polymers.

Peer Reviewed