The hydrophilicity of the extracellular matrix is one of the most important factors affecting cell adhesion in tissue engineering. In the present study, to improve the cellular biocompatibility of poly(epsilon-caprolactone) (PCL) nanofiber scaffolds, their surface hydrophilicity was enhanced by electrospinning PCL with biocompatible, amphiphilic poly(N-vinylpyrrolidone)-b-PCL (PVP-b-PCL) block copolymer. The PVP-b-PCL block copolymer (M-n = 26,300 g/mol, M-w/M-n = 1.14) was synthesized using 2-hydroxyethyl 2(ethoxycarbonothioylthio)propanoate as a dual initiator for reversible addition-fragmentation chain transfer polymerization and ring opening polymerization in a one-pot procedure. As the content of PVP-b-PCL block copolymer increased, the surface of the PCL/PVP-b-PCL nanofiber scaffolds became more hydrophilic. The scaffolds showed no cytotoxicity, better cell adhesion, and improved viability of primary fibroblasts than PCL scaffolds, and did not lose their structure during cell culture. In particular, the PCL/PVP-b-PCL (90/10, w/w) nanofiber scaffold produced the highest cell viability, suggesting that appropriate scaffold hydrophilicity is required to enhance cell activity. (C) 2015 Elsevier Ltd. All rights reserved.