title: The influence of substrate creep on mesenchymal stem cell behaviour and phenotype.
abstract: Human mesenchymal stem cells (hMSCs) are capable of probing and responding to the mechanical properties of their substrate. Although most biological and synthetic matrices are viscoelastic materials, previous studies have primarily focused upon substrate compressive modulus (rigidity), neglecting the relative contributions that the storage (elastic) and loss (viscous) moduli make to the summed compressive modulus. In this study we aimed to isolate and identify the effects of the viscous component of a substrate on hMSC behaviour. Using a polyacrlyamide gel system with constant compressive modulus and varying loss modulus we determined that changes to substrate loss modulus substantially affected hMSC morphology, proliferation and differentiation potential. In addition, we showed that the effect of substrate loss modulus on hMSC behaviour is due to a reduction in both passive and actively generated isometric cytoskeletal tension caused by the inherent creep of substrates with a high loss modulus. These findings highlight substrate creep, or more explicitly substrate loss modulus, as an important mechanical property of a biomaterial system that can be tailored to encourage the growth and differentiation of specific cell types.
authors.affiliation: Tissue Engineering and Microfluidics Laboratory, Australian Institute for Bioengineering and Nanotechnology, Building 75-Cnr of College and Cooper Road, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Cameron
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Frith
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Cooper-White
mesh_terms: D001672:Biocompatible Materials / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D055119:Elastic Modulus; D004548:Elasticity; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials