Nitric oxide (NO)-generating materials are beneficial for vascular tissue engineering (VTE) scaffold because the produced NO would enhance endothelial cells viability while inhibit smooth muscle cell (SMC) proliferation and reduce platelet adhesion, resulting in ideal hemocompatibility and endothelialization. Herein, poly(epsilon-caprolactone) (PCL)/keratin biocomposite mats were first fabricated, followed by in situ gold (Au) nanoparticles loading to afford PCL/keratin/AuNPs mats. These mats were characterized using field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The PCL/keratin/AuNPs mats were demonstrated to be capable of catalyzing NO release in the mimicked blood microenvironments. The generated NO could enhance human umbilical vein endothelial cell growth and inhibit human umbilical arterial SMC viability. In addition, these mats maintained the antibacterial activity of Au nanoparticles with good blood compatibility. Taken together, these keratin-based composite mats have potential usage in the VTE. (c) 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3239-3247, 2018.