Macroporous elastomeric scaffolds with extensive micropores for soft tissue engineering

Macroporous scaffolds are of great value in tissue engineering. We have developed a method to fabricate macroporous scaffolds from a biocompatible and biodegradable elastomer, poly(glycerol sebacate) (PGS). This method is potentially very useful for soft tissue engineering. Our fabrication method produced macroporous scaffolds with extensive micropores. We fabricated flat scaffolds and tubular scaffolds of uniform thickness. This fabrication method demonstrated good control of variables such as pore size, porosity, and pore interconnectivity. Sodium chloride (salt) crystals, which served as solid porogens, were packed into a mold and fused in a humid chamber. PGS was cured while dispersed throughout the fused salt template. Dissolution of the salt and subsequent lyophilization produced elastomer sponges with approximately 90% porosity, interconnected macropores (75-150 microm), and extensive micropores (5-20 microm). The macropores were generated by the salt particles, while the micropores were likely generated by glycerol vapor formed during PGS curing. Such numerous micropores could facilitate cell-cell interactions and mass transport. Fibroblasts adhered to and proliferated well within the PGS scaffolds and formed three-dimensional tissue-engineered constructs within 8 days.