title: Low oxygen tension and synthetic nanogratings improve the uniformity and stemness of human mesenchymal stem cell layer.
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.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Veldhuis
authors.forename: Yajun
authors.initials: Y
authors.lastname: Duan
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Nicolas
authors.initials: N
authors.lastname: Christoforou
authors.forename: Teng
authors.initials: T
authors.lastname: Ma
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
mesh_terms: D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D007150:Immunohistochemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D049329:Nanostructures / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D010100:Oxygen