Differential regulation of morphology and stemness of mouse embryonic stem cells by substrate stiffness and topography

• Published in: Biomaterials Vol. 35; no. 13; pp. 3945 - 3955
• Main Authors: Lü, Dongyuan, Luo, Chunhua, Zhang, Chen, Li, Zhan, Long, Mian
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.04.2014
• Subjects: Advanced Basic Science; Animals; Cell Differentiation - genetics; Cell Differentiation - physiology; Cell Proliferation - genetics; Cell Proliferation - physiology; Cells, Cultured; Dentistry; Embryonic Stem Cells - cytology; Embryonic Stem Cells - metabolism; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Mice; Morphology; Nanog Homeobox Protein; Octamer Transcription Factor-3 - genetics; Octamer Transcription Factor-3 - metabolism; Stem cell; Stemness; Stiffness; Topography; conditioned medium; PS; 2-ME; Stem cell; mESCs; 2D; three-dimensional; RFI; Topography; Stiffness; mouse embryonic fibroblasts; MSC; polyacrylamide; embryoid bodies; Stemness; MEFs; nonessential amino acids; polystyrene; knockout serum replacement; LIF; CM; poly-dimethylsiloxane; KSR; ECM; beta-mercaptoethanol; PA; 3D; NEAA; PLGA; two-dimensional; Morphology; mesenchymal stem cells; relative fluorescent intensity; EBs; mouse embryonic stem cells; poly(lactic-co-glycolic acid); leukemia inhibitory factor; extracellular matrix; PDMS
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/j.biomaterials.2014.01.066

Abstract The maintenance of stem cell pluripotency or stemness is crucial to embryonic development and differentiation. The mechanical or physical microenvironment of stem cells, which includes extracellular matrix stiffness and topography, regulates cell morphology and stemness. Although a growing body of evidence has shown the importance of these factors in stem cell differentiation, the impact of these biophysical or biomechanical regulators remains insufficiently characterized. In the present study, we applied a micro-fabricated polyacrylamide hydrogel substrate with two elasticities and three topographies to systematically test the morphology, proliferation, and stemness of mESCs. The independent or combined impact of the two factors on specific cell functions was analyzed. Cells are able to grow effectively on both polystyrene and polyacrylamide substrates in the absence of feeder cells. Substrate stiffness is predominant in preserving stemness by enhancing Oct-4 and Nanog expression on a soft polyacrylamide substrate. Topography is also a critical factor for manipulating stemness via the formation of a relatively flattened colony on a groove or pillar substrate and a spheroid colony on a hexagonal substrate. Although topography is less effective on soft substrates, it plays a role in retaining cell stemness on stiff, hexagonal or pillar-shaped substrates. mESCs also form, in a timely manner, a 3D structure on groove or hexagonal substrates. These results further the understanding of stem cell morphology and stemness in a microenvironment that mimics physiological conditions.