Fabrication of poly(α-hydroxy acid) foam scaffolds using multiple solvent systems

The present studies describe the fabrication and characterization of highly porous and interconnected poly(alpha -hydroxy acid) foam scaffolds produced using a phase separation multisolvent system, followed by a sublimation process. Fabrication parameters, including solvent composition, polymer concentration, freezing temperature, polymer type, and polymer molecular weight, were optimized to produce the desired foam microstructure. Analyses of selected samples with scanning electron microscopic images and mercury intrusion porosimetry indicated polymer foams with pore size ranges of 100-350 mum, a porosity >90%, and an interconnecting open-pore foam structure. Scaffold degradation profiles varied according to the type and molecular weight of the polymers. Cytocompatibility assays demonstrated that the preferred foam structures were nontoxic and osteoprecursor cells seeded into the scaffolds exhibited the ability to attach, propagate, and differentiate into a calcified structure. (C) 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 563-572, 2002.