Biomedical polyurethane (PU) and silk fibroin have similar molecular architecture in their primary and aggregate structure, both of which have imido bonds and microphase separation, and they have been employed as scaffold materials for biomedical applications. As the featured peptide sequence of silkworm silk protein, GlyAlaGlyAla (GAGA) tetrapeptide was synthesized by using traditional liquid-phase peptide synthesis method with Boc-protected alanine and glycine as starting materials, and was transformed to its derivative with two end-amido groups. The derivative was incorporated into the backbone of the classical synthetic copolyurethane as a chain extender to form a silk-inspired polyurethane. Elemental analysis showed the nitrogen content in the silk-inspired PU was higher than that in the butanediol-extended PU but lower than the theoretical value, indicating the chain extender containing GAGA was partially incorporated into the PU chain. The results from IN-nuclear magnetic resonance, Fourier transform infrared spectra, Raman scattering spectra and pyrolysis-gas chromatography/mass spectrometry qualitatively identified the primary structure of the silk-inspired polyurethane. This concept and strategy may allow the fabrication of a new class of thermoplastic polyurethane elastomer to mimic the structure and properties of silk fibers if in fiber form, which combines traditional synthetic polymer chains with peptide sequences. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 235-242, 2010