Papers Published

  1. Zhao, F. and Veldhuis, J. J. and Duan, Y. J. and Yang, Y. and Christoforou, N. and Ma, T. and Leong, K. W., Low Oxygen Tension and Synthetic Nanogratings Improve the Uniformity and Stemness of Human Mesenchymal Stem Cell Layer, Molecular Therapy, vol. 18 no. 5 (2010), pp. 1010-1018 .
    (last updated on 2010/06/11)

    Abstract:
    A free-standing, robust cell sheet comprising aligned human mesenchymal stem cells (hMSCs) offers many interesting opportunities for tissue reconstruction. As a first step toward this goal, a confluent, uniform hMSC layer with a high degree of alignment and stemness maintenance needs to be created. Hypothesizing that topographical cue and a physiologically relevant low-oxygen condition could promote the formation of such an hMSC layer, we studied the culture of hMSCs on synthetic nanogratings (350 nm width and 700 nm pitch) and either under 2 or 20% O-2. Culturing hMSCs on the nanogratings highly aligned the cells, but it tended to create patchy layers and accentuate the hMSC differentiation. The 2% O-2 improved the alignment and uniformity of hMSCs, and reduced their differentiation. Over a 14-day culture period, hMSCs in 2% O-2 showed uniform connexon distribution, secreted abundant extracellular matrix (ECM) proteins, and displayed a high progenicity. After 21-day culture on nanogratings, hMSCs exposed to 2% O-2 maintained a higher viability and differentiation capacity. This study established that a 2% O-2 culture condition could restrict the differentiation of hMSCs cultured on nanopatterns, thereby setting the foundation to fabricate a uniformly aligned hMSC sheet for different regenerative medicine applications.

    Keywords:
    marrow stromal cells smooth-muscle-cells extracellular-matrix osteogenic differentiation gene-expression hypoxia tissues organization myocardium infarction