Long-term stimulation with alternating electric fields modulates the differentiation and mineralization of human pre-osteoblasts

Franziska Sahm; Vivica Freiin Grote; Julius Zimmermann; Fiete Haack; Adelinde M Uhrmacher; Ursula van Rienen; Rainer Bader; Rainer Detsch; Anika Jonitz-Heincke

doi:10.3389/fphys.2022.965181

Long-term stimulation with alternating electric fields modulates the differentiation and mineralization of human pre-osteoblasts

Front Physiol. 2022 Sep 30:13:965181. doi: 10.3389/fphys.2022.965181. eCollection 2022.

Authors

Affiliations

¹ Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Centre, Rostock, Germany.
² Chair of Theoretical Electrical Engineering, Institute for General Electrical Engineering, University of Rostock, Rostock, Germany.
³ Institute for Visual and Analytic Computing, University of Rostock, Rostock, Germany.
⁴ Department Life, Light and Matter, University of Rostock, Rostock, Germany.
⁵ Department Ageing of Individuals and Society, University of Rostock, Rostock, Germany.
⁶ Department of Materials Science and Engineering, Institute of Biomaterials, Friedrich Alexander-University Erlangen-Nuremberg, Erlangen, Germany.

Abstract

Biophysical stimulation by electric fields can promote bone formation in bone defects of critical size. Even though, long-term effects of alternating electric fields on the differentiation of osteoblasts are not fully understood. Human pre-osteoblasts were stimulated over 31 days to gain more information about these cellular processes. An alternating electric field with 0.7 V_rms and 20 Hz at two distances was applied and viability, mineralization, gene expression, and protein release of differentiation factors were analyzed. The viability was enhanced during the first days of stimulation. A higher electric field resulted in upregulation of typical osteogenic markers like osteoprotegerin, osteopontin, and interleukin-6, but no significant changes in mineralization. Upregulation of the osteogenic markers could be detected with a lower electric field after the first days of stimulation. As a significant increase in the mineralized matrix was identified, an enhanced osteogenesis due to low alternating electric fields can be assumed.

Keywords: alternating fields; bone remodeling; differentiation; electric stimulation; long-term stimulation; pre-osteoblasts.