Introduction Biocompatible and biodegradable polyurethanes have been investigated as scaffolds for tissue engineering applications for almost twenty years. To avoid the toxic diamine decomposition products from aromatic diisocyanates, aliphatic diisocyanates, such as methyl 2,6-diisocyanatohexanoate (lysine methyl ester diisocyanate, or LDI), have been used to synthesize biodegradable polyurethanes. Porous polyurethane scaffolds have been prepared from LDI and polyols by incorporating a porogen (e.g., salt or gelatin) or water, which reacts with isocyanate to form carbon dioxide, a biocompatible blowing agent. In vitro and in vivo studies have demonstrated that porous polyurethane scaffolds prepared from LDI and polyester (or polyether) polyols degrade to non-toxic by-products and support the migration of cells and growth of new tissue. Polyurethanes are potentially useful for injectable scaffolds because they comprise a reactive two-component system. By mixing two liquid components, a solid polymer can be formed and cured in vivo. To be clinically useful, the injectable scaffold must have high porosity to facilitate the ingrowth of cells and new tissue, be dimensionally stable, rise quickly, and degrade at a controlled rate to biocompatible degradation products. In this study, we synthesized porous polyurethane foams from LDI and a 70/30 poly(ecaprolactone-co-glycolide) triol. Sulfated castor oil (Turkey red oil) and the polyethersiloxane TEGOSTAB 8300 were used as stabilizers to emulsify the raw materials and stabilize the rising bubbles. Calcium stearate was added as a cell opener. Triethylene diamine (TEDA, sold as TEGOAMIN33) was used as a tertiary amine catalyst.