Impact of grain structure of austenitic stainless steel on osteoblasts differention and mineralisation

Abstract

There is currently a strong interest in nano- and ultrafine grained planar surface and coatings in the biomedical community, but there is a lack of understanding with regard to the interplay between grain size and cell differentiation. Motivated by our previous studies on the interplay between grain structure and biological response, we describe here the influence of grain size from nano- to coarse grain on osteoblast differentiation and mineralisation. This aspect constitutes the objective of the study. Experiments on the interplay between grain structure and osteoblast functions indicated that cell differentiation and mineralisation varied with grain size and were favourably modulated on the nanograin (NG) and ultrafine grain (UFG) surface, consistent with alkaline phosphatase activity. Furthermore, it is elucidated that the grain structure strongly influences the ability of the surface to form a well mineralised bone-like extracellular matrix by secreting bone markers, which in turn is governed by grain structure–hydrophilicity relationship. The study demonstrates potential for a new branch of nanostructured materials for biomedical applications.

Keywords:

• Grain size
• Osteoblasts
• Differentiation
• Mineralisation

Acknowledgements

The authors gratefully thank Board of Regents of Louisiana for support through grant no. LEQSF (2012-15) RD-B-08 for processing as part of advanced high strength steels.