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Simultaneous determination of Young’s modulus, shear modulus, and Poisson’s ratio of soft hydrogels

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Abstract

Besides biological and chemical cues, cellular behavior has been found to be affected by mechanical cues such as traction forces, surface topology, and in particular the mechanical properties of the substrate. The present study focuses on completely characterizing the bulk linear mechanical properties of such soft substrates, a good example of which are hydrogels. The complete characterization involves the measurement of Young’s modulus, shear modulus, and Poisson’s ratio of these hydrogels, which is achieved by manipulating nonspherical magnetic microneedles embedded inside them. Translating and rotating these microneedles under the influence of a known force or torque, respectively, allows us to determine the local mechanical properties of the hydrogels. Two specific hydrogels, namely bis-cross-linked polyacrylamide gels and DNA cross-linked polyacrylamide gels were used, and their properties were measured as a function of gel concentration. The bis-cross-linked gels were found to have a Poisson’s ratio that varied between 0.38 and 0.49, while for the DNA-cross-linked gels, Poisson’s ratio varied between 0.36 and 0.49. The local shear moduli, measured on the 10 µm scale, of these gels were in good agreement with the global shear modulus obtained from a rheology study. Also the local Young’s modulus of the hydrogels was compared with the global modulus obtained using bead experiments, and it was observed that the inhomogeneities in the hydrogel increases with increasing cross-linker concentration. This study helps us fully characterize the properties of the substrate, which helps us to better understand the behavior of cells on these substrates.

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References

  1. U. Chippada, B. Yurke, P.C. Georges, N.A. Langrana A nonintrusive method of measuring the local mechanical properties of soft hydrogels using magnetic microneedles. J. Biomech. Eng. 131, 021014 (2009)

    Article  Google Scholar 

  2. J.W. Gunn, S.D. Turner, B.K. Mann Adhesive and mechanical properties of hydrogels influence neurite extension. J. Biomed. Mater. Res. Part A 72, (1) 91 (2005)

    Article  Google Scholar 

  3. C.B. Khatiwala, S.R. Peyton, A.J. Putnam Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells. Am. J. Physiol. Cell Physiol. 290, (6) 1640 (2006)

    Article  Google Scholar 

  4. P.C. Georges, P.A. Janmey Cell type-specific response to growth on soft materials. Am. Physiological Soc. 98, 1547 (2005)

    Google Scholar 

  5. R.J. Pelham, Y. Wang Cell locomotion and focal adhesions are regulated by substrate flexibility. Proc. Natl. Acad. Sci. U.S.A. 94, 13661 (1997)

    Article  CAS  Google Scholar 

  6. C.M. Lo, H.B. Wang, M. Dembo, Y. Wang Cell movement is guided by the rigidity of the substrate. Biophys. J. 79, (1) 144 (2000)

    Article  CAS  Google Scholar 

  7. F.X. Jiang, B. Yurke, B.L. Firestein, N.A. Langrana Neurite outgrowth on a DNA crosslinked hydrogel with tunable stiffnesses. Ann. Biomed. Eng. 36, (9) 1565 (2008)

    Article  Google Scholar 

  8. F. Horkay, M. Zrinyi Studies on the mechanical and swelling behavior of polymer networks based on the scaling concept. 4. Extension of the scaling approach to gels swollen to equilibrium in a diluent of arbitrary activity. Macromolecules 15, (5) 1306 (1982)

    Article  CAS  Google Scholar 

  9. N. Gundogan, D. Melekaslan, O. Okay Rubber elasticity of poly (N-isopropylacrylamide) gels at various charge densities. Macromolecules 35, (14) 5616 (2002)

    Article  CAS  Google Scholar 

  10. J.Y. Wong, A. Velasco, P. Rajagopalan, Q. Pham Directed movement of vascular smooth muscle cells on gradient-compliant hydrogels. J. Cell Sci. 112, 1967 (1999)

    Google Scholar 

  11. M. Radmacher, R.W. Tillamnn, M. Fritz, H.E. Gaub From molecules to cells: Imaging soft samples with the atomic force microscope. Science 257, (5078) 1900 (1992)

    Article  CAS  Google Scholar 

  12. M. Radmacher, M. Fritz, C.M. Kacher, J.P. Cleveland, P.K. Hansma Measuring the viscoelastic properties of human platelets with the atomic force microscope. Biophys. J. 70, (1) 556 (1996)

    Article  CAS  Google Scholar 

  13. D.C. Lin, B. Yurke, N.A. Langrana Inducing reversible stiffness changes in DNA-crosslinked gels. J. Mater. Res. 20, (6) 1456 (2005)

    Article  CAS  Google Scholar 

  14. D.C. Lin, B. Yurke, N.A. Langrana Mechanical properties of a reversible, DNA-crosslinked polyacrylamide hydrogel. J. Biomech. Eng. 126, 104 (2004)

    Article  Google Scholar 

  15. D.C. Lin, B. Yurke, N.A. Langrana Use of rigid spherical inclusions in Young’s moduli determination: Application to DNA-crosslinked gels. J. Biomech. Eng. 127, 571 (2005)

    Article  Google Scholar 

  16. E. Geissler, A.M. Hecht The Poisson ratio in polymer gels. 2. Macromolecules 14, (1) 185 (1981)

    Article  CAS  Google Scholar 

  17. S. Hirotsu Static and time-dependent properties of polymer gels around the volume phase transition. Phase Transitions 47, (3) 183 (1994)

    Article  CAS  Google Scholar 

  18. T. Takigawa, Y. Morino, K. Urayama, T. Masuda Poisson’s ratio of polyacrylamide (PAAm) gels. Polym. Gels Networks 4, (1) 1 (1996)

    Article  CAS  Google Scholar 

  19. S. Hirotsu Softening of bulk modulus and negative Poisson’s ratio near the volume phase transition of polymer gels. J. Chem. Phys. 94, 3949 (1991)

    Article  CAS  Google Scholar 

  20. L.A. Flanagan, Yo-El B.M. Ju, M. Osterfield, P.A. Janmey Neurite branching on deformable substrates. Neuroreport 13, (18) 2411 (2002)

    Article  Google Scholar 

  21. P.C. Georges, W.J. Miller, D.F. Meaney, E.S. Sawyer, P.A. Janmey Matrices with compliance comparable to that of brain tissue select neuronal over glial growth in mixed cortical cultures. Biophys. J. 90, (8) 3012 (2006)

    Article  CAS  Google Scholar 

  22. E.J. Semler, C.S. Ranucci, P.V. Moghe Tissue assembly guided via substrate biophysics: Applications to hepatocellular engineering. Adv. Biochem. Eng./ Biotechnol. 102, 1 (2006)

    CAS  Google Scholar 

  23. N.J. Tao, S.M. Lindsay, S. Lees Measuring the microelastic properties of biological material. Biophys. J. 63, (4) 1165 (1992)

    Article  CAS  Google Scholar 

  24. Z. Shao, J. Mou, D.M. Czajkowsky, J. Yang, J.Y. Yuan Biological atomic force microscopy: What is achieved and what is needed. Adv. Phys. 45, (1) 1 (1996)

    Article  CAS  Google Scholar 

  25. L. Benguigui, Boué F. Homogeneous and inhomogenous polyacrylamide gels as observed by small angle neutron scattering: A connection with elastic properties. Eur. Phys. J. B 11, (3) 439 (1999)

    Article  CAS  Google Scholar 

  26. S. Durmaz, O. Okay Inhomogeneities in poly (acrylamide) gels: Position-dependent elastic-modulus measurements. Polym. Bull. 46, (5) 409 (2001)

    Article  CAS  Google Scholar 

  27. R. Skomski, J.M.D. Coey Permanent Magnetism (Institute of Physics Publishing, Philadelphia, PA 1999)

    Google Scholar 

  28. Q.A. Pankhurst, J. Connolly, S.K. Jones, J. Dobson Applications of magnetic nanoparticles in biomedicine. J. Phys. D: Appl. Phys. 36, (13) 167 (2003)

    Article  Google Scholar 

  29. L.J. Walpole A translated rigid ellipsoidal inclusion in an elastic medium. Proc.: Math. Phys. Sci. 434, (1892) 571 (1991)

    Google Scholar 

  30. L.J. Walpole A rotated rigid ellipsoidal inclusion in an elastic medium. Proc.: Math. Phys. Sci. 433, (1887) 179 (1991)

    Google Scholar 

  31. U. Chippada, B. Yurke, N.A. Langrana Complete mechanical characterization of soft media using non-spherical rods. J. Appl. Phys. 106, (6) 63528 (2009)

    Article  Google Scholar 

  32. Y. Cohen, O. Ramon, I.J. Kopelman, S. Mizrahi Characterization of inhomogeneous polyacrylamide hydrogels. J. Polym. Sci. Part B: Polym. Phys. 30, (9) 1055 (1992)

    Article  CAS  Google Scholar 

  33. E. Geissler, A.M. Hecht The Poisson ratio in polymer gels. Macromolecules 13, (5) 1276 (1980)

    Article  CAS  Google Scholar 

  34. Y. Li, Z. Hu, C. Li New method for measuring Poisson’s ratio in polymer gels. J. Appl. Polym. Sci. 50, (6) 1107 (1993)

    Article  CAS  Google Scholar 

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Correspondence to Noshir A. Langrana.

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Chippada, U., Yurke, B. & Langrana, N.A. Simultaneous determination of Young’s modulus, shear modulus, and Poisson’s ratio of soft hydrogels. Journal of Materials Research 25, 545–555 (2010). https://doi.org/10.1557/JMR.2010.0067

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