Surface terracing on ferritic stainless-steel fibres and potential relevance to in vitro cell growth

Abstract

Since many natural and biological materials are cellular, often with relatively high porosity levels (although sometimes these pores are partly filled with a fluid or a soft and compliant solid in the natural state), various types of porous materials are of interest for biological applications. A key feature for such applications is the space afforded for invasion, first by cells and ultimately by osseous tissue and vasculature. The surface should be chemically and topologically suitable for cells to penetrate and interlock. There is evidence that fine scale topographic features can affect both the adhesion and ingrowth of cells. One way of creating topographic features, such as terraces, is to employ suitable heat treatments so as to expose preferentially the low surface energy crystallographic planes via surface diffusion. The topography and crystallography of surface terraces, generated on solid-state-sintered ferritic stainless-steel fibre networks, have been characterised by electron back-scattered diffraction, atomic force microscopy and scanning electron microscopy. Initial work on the effect of these fine scale topographic features on cell proliferation shows encouraging results.

Keywords:

• EBSD
• fibres
• stainless steel
• surface energy
• cell growth

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Erratum

Acknowledgements

Financial support for AEM and RAO has been provided via an EPSRC Advanced Research Fellowship and a Royal Society University Research Fellowship, respectively. We are particularly grateful to Prof. T.W. Clyne, of the Materials Science Department in Cambridge, for useful discussions. We would also like to thank Olaf Andersen from IFAM Dresden for providing information regarding the HT1 heat treatment, Dr. Meera Arumugam of The University of Cambridge Orthopaedic Research Unit for useful discussions on cell culture, and Lee Marston and Peter Rooney, of Fibretech Ltd., for extensive collaboration and cooperation, including the provision of fibres.