In order to achieve effective bone regeneration, the architectural/structural and biological environment must be considered. In this study, we investigated the influence of structure of extracellular matrix-mimicking electrospun poly (L-lactic acid) (PLLA) fibrous scaffolds and incorporated growth factors (bone morphogenetic protein2 (BMP2) and platelet-derived growth factor (PDGF)) (GFs) on in vitro differentiation of human mesenchymal stem cells (hMSCs) cultured onto the scaffolds. Furthermore, Cargo GFs were first encapsulated into coacervate (Coa). Coa-coated nano-sized PLLA (Coa-nPLLA) exhibited relatively higher coating efficacy, than Coa-coated micro-sized PLLA (Coa-mPLLA) due to large mesh hole area of mPLLA. Consequently, a faster GF release pattern was observed in nPLLA groups. As a result of osteogenic differentiation of hMSC which cultured onto GFs loaded Coa-PLLA, the architectural cue of fiber diameters effectively modulated early osteogenic differentiation of hMSCs. Facilitated long-term differentiation of hMSCs could be achieved by synergistic effect of dual BMP2 and PDGF in nanofbrous environments. (C) 2019 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.