Alternative strategies are required when autograft tissue is not sufficient or available to reconstruct damaged tendons. Electrospun fibre yams could provide such an alternative. This study investigates the seeding of human mesenchymal stem cells (hMSC) on electrospun yarns and their response when subjected to dynamic tensile loading. Cell seeded yams sustained 3600 cycles per day for 21 days. Loaded yams demonstrated a thickened cell layer around the scaffold's exterior compared to statically cultured yams, which would suggest an increased rate of cell proliferation and/or matrix deposition, whilst maintaining a predominant uniaxial cell orientation. Tensile properties of cell-seeded yams increased with time compared to acellular yams. Loaded scaffolds demonstrated an up-regulation in several key tendon genes, including collagen Type I. This study demonstrates the support of hMSCs on electrospun yams and their differentiation towards a tendon lineage when mechanically stimulated. (C) 2014 The Authors. Published by Elsevier Ltd.