Analytical and Bioanalytical Chemistry

, Volume 396, Issue 8, pp 3009–3015 | Cite as

Development of an electrode cell impedance method to measure osteoblast cell activity in magnesium-conditioned media

  • YeoHeung Yun
  • Zhongyun Dong
  • Zongqing Tan
  • Mark J. Schulz
Original Paper


Magnesium (Mg) as a biodegradable metal has potential advantages as an implant material. This paper studies the effect of magnesium ions on osteoblast (U2-OS) behavior since magnesium implants mainly dissolve as divalent magnesium ions (Mg2+). A real-time monitoring technique based on electric cell-substrate impedance sensing (ECIS) was used for measuring cell proliferation, migration, adhesion, and cytotoxicity in magnesium-conditioned media. The impedance results show that U2-OS proliferation and adhesion were inhibited in not only a magnesium-free medium but also in a medium with a high concentration of magnesium. The impedance method produced more sensitive results than the output of an MTT assay. Other standard bioanalytical tests were conducted for comparison with the ECIS method. Immunochemistry was carried out to study cell adhesion in magnesium-conditioned media by staining using F-actin and α-tubulin and correlated cell density on the electrode with impedance. Bone tissue formation was studied using von Kossa staining and indicated the mineralization level of cells in magnesium-conditioned media decreased with the increase of magnesium ion concentration. Real-time PCR provided gene expression indicators of cell growth, apoptosis, inflammation, and migration. Compared to the bioanalytical methods of immunochemistry and MTT assays, which need preparation time and post-washing step, ECIS was able to measure cell activity in real time without any cell culture modification. In summary, ECIS might be an effective way to study biodegradable magnesium implants.


Principle of ECIS for analyzing U2-OS cell behavior under different concentrations of magnesium: a osteoblast cells are floating in the medium and the electrode impedance is small; and b osteoblast cells create a monolayer on the electrode which increases the impedance


Biodegradable magnesium implant U2-OS cells Electric cell-substrate impedance sensing (ECIS) Cytotoxicity MTT assay Real-time PCR 



This work was sponsored by the NSF ERC for Revolutionizing Metallic Biomaterials,


  1. 1.
    Yun Y, Dong Z, Yang D, Schulz M, Shanov V, Yarmolenko S, Xu Z, Kumta P, Sfeir C (2009) Mat Sci Eng: C 29:1814–1821CrossRefGoogle Scholar
  2. 2.
    Witte F, Feyerabend F, Maier P, Fischer J, Störmer M, Blawert C, Dietzel W, Hort N (2007) Biomaterials 28:2163–74CrossRefGoogle Scholar
  3. 3.
    Li Z, Gu X, Lou S, Zheng Y (2008) Biomaterials 29:1329–44CrossRefGoogle Scholar
  4. 4.
    Zeng R, Dietzel W, Witte F, Hort N (2008) Blawert C 10:B3–B14Google Scholar
  5. 5.
    Hiromoto S, Shishido T, Yamamoto A, Maruyama N, Somekawa H (2008) Mukai T Corrosion Science 50:2906–2913CrossRefGoogle Scholar
  6. 6.
    Song G (2007) Song S 9:298–302Google Scholar
  7. 7.
    Lorenz C, Brunnera J, Kollmannsberger P, Jaafar L, Fabry B, Virtanena S (2009) Acta Biomaterialia 5:2783–2789Google Scholar
  8. 8.
    Xu L, Pan F, Yu G, Yang L, Zhang E, Yang K (2009) Biomaterials 30:1512–23CrossRefGoogle Scholar
  9. 9.
    Yun Y, Dong Z, Lee N, Liu Y, Xue D, Guo X, Kuhlmann J, Doepke A, Halsall B, Heineman W, Sundaramurthy S, Schulz M, Yin Z, Shanov V, Hurd D, Nagy P, Li W, Fox C (2009) Materials Today 12:22–32CrossRefGoogle Scholar
  10. 10.
    Rubin H (2005) BioEssays 27:311–320CrossRefGoogle Scholar
  11. 11.
    Wolf F, Trapani V (2008) Clinical Science 114:27–35CrossRefGoogle Scholar
  12. 12.
    Günther T (2008) Magnes Res 21:185–187Google Scholar
  13. 13.
    Hornby J (1973) Embryol Exp Morph 30:511–518Google Scholar
  14. 14.
    Turner D, Flier L, Carbonetto S (1987) Dev Biol 121:510–525CrossRefGoogle Scholar
  15. 15.
    Li C, Gao S, Terashita T, Shimokawa T, Kawahara H, Matsuda S, Kobayashi N (2006) Cell and Tissue Research 324:396–375CrossRefGoogle Scholar
  16. 16.
    Rouahi M, Champion E, Hardouin P, Anselme K (2006) Biomaterials 27:2829–2844CrossRefGoogle Scholar
  17. 17.
    Anselme K (2000) Biomaterials 21:667–681CrossRefGoogle Scholar
  18. 18.
    Zreiqat H, Howlett CR, Zannettino A, Evans P, Schulze-Tanzil G, Knabe C (2002) Shakibaei M J Biomed Mater Res 62:175–184CrossRefGoogle Scholar
  19. 19.
    Diener A, Nebe B, Lüthen F, Becker P, Beck U, Neumann HG, Rychly J (2005) Biomaterials 26:383–392CrossRefGoogle Scholar
  20. 20.
    Abed E, Moreau R (2010) Am J Physiol Cell Physiol 297:C360–368Google Scholar
  21. 21.
    Spillmann C, Osorio D, Waugh R (2002) Ann Biomed Eng 30:1002–1011CrossRefGoogle Scholar
  22. 22.
    Maier JA, Bernardini D, Rayssiguier Y, Mazur A (2004) Biochim Biophys Acta 24:6–12Google Scholar
  23. 23.
    Moomaw AS, Maguire ME (2008) Physiology (Bethesda) 23:275–285Google Scholar
  24. 24.
    Bo S, Pisu E (2008) Curr Opin Lipidol 19:50–56CrossRefGoogle Scholar
  25. 25.
    Günther T (2006) Magnes Res 19:225–36Google Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • YeoHeung Yun
    • 1
  • Zhongyun Dong
    • 2
  • Zongqing Tan
    • 2
  • Mark J. Schulz
    • 1
  1. 1.Smart Materials Nanotechnology Laboratory, Dept. of Mechanical EngineeringUniversity of CincinnatiCincinnatiUSA
  2. 2.Department of Internal Medicine, College of MedicineUniversity of CincinnatiCincinnatiUSA

Personalised recommendations