Deciphering the combinatorial roles of geometric, mechanical, and adhesion cues in regulation of cell spreading

• Published in: PloS one Vol. 8; no. 11; p. e81113
• Main Authors: Harris, Greg M, Shazly, Tarek, Jabbarzadeh, Ehsan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25-11-2013; Public Library of Science (PLoS)
• Subjects: Biomedical engineering; Biomedical materials; Cell Adhesion; Cell adhesion & migration; Cell Movement; Cell spreading; Cells, Cultured; Chemical engineering; Combinatorial analysis; Cues; Decoupling; Elasticity; Extracellular Matrix; Finite Element Analysis; Finite element method; Fluorescent Antibody Technique; Humans; Hydrogels; Interfaces; Islands; Ligands; Mesenchymal Stem Cells - cytology; Mesenchymal Stem Cells - enzymology; Mesenchyme; Microenvironments; Motility; Nanotechnology; Pattern formation; Physical characteristics; Physical properties; Polyethylene glycol; Proteins; Regenerative medicine; rho-Associated Kinases - antagonists & inhibitors; RhoA protein; Signal transduction; Signaling; Spreading; Stem cells; Studies; Substrates; Tissue engineering; Topography; United States > US; South Carolina
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0081113

Significant effort has gone towards parsing out the effects of surrounding microenvironment on macroscopic behavior of stem cells. Many of the microenvironmental cues, however, are intertwined, and thus, further studies are warranted to identify the intricate interplay among the conflicting downstream signaling pathways that ultimately guide a cell response. In this contribution, by patterning adhesive PEG (polyethylene glycol) hydrogels using Dip Pen Nanolithography (DPN), we demonstrate that substrate elasticity, subcellular elasticity, ligand density, and topography ultimately define mesenchymal stem cells (MSCs) spreading and shape. Physical characteristics are parsed individually with 7 kilopascal (kPa) hydrogel islands leading to smaller, spindle shaped cells and 105 kPa hydrogel islands leading to larger, polygonal cell shapes. In a parallel effort, a finite element model was constructed to characterize and confirm experimental findings and aid as a predictive tool in modeling cell microenvironments. Signaling pathway inhibition studies suggested that RhoA is a key regulator of cell response to the cooperative effect of the tunable substrate variables. These results are significant for the engineering of cell-extra cellular matrix interfaces and ultimately decoupling matrix bound cues presented to cells in a tissue microenvironment for regenerative medicine.