In this article, tissue-engineering scaffolds were fabricated from P(epsilon-CL-co-D,L-LA)-PEG-P(epsilon-CL-co-D,L-LA) copolymers using co-continuous blends with polystyrene as the porogen phase. By means of static annealing and following extraction of the porogen phase, pore sizes (channel widths) in the range of 1.5-350 mu m were obtained. Smooth muscle cells were seeded in three-dimensional fibronectin-modified scaffolds of two different pore sizes. Considerably enhanced cell seeding efficiency was found for scaffolds with larger pore sizes, indicating the importance of this parameter to promote effective cell intrusion into bulk materials. Compressive moduli ranged from 2.3 +/- 0.3 to 67 +/- 15 MPa and decreased with increasing pore size. The reverse trend was found for scaffold permeability (kappa), which ranged from 8.5 x 10(-16) to 6.7 x 10(-11) m(2). This was comparable with permeabilities previously reported for scaffolds with higher pore sizes and void volumes, but more irregular pore morphologies. Taken together, the results obtained in this study motivate further investigation for possible future applications in tissue engineering. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 91A: 305-315,2009