Electrical Stimulation In Bone Cell Culture Media

Abstract

Osteocytes are the most abundant bone cells, however, they are also the least understood. They sense mechanical stress within the bone matrix to control remodelling, but there is debate about the way that this occurs. The bone matrix experiences changes in electrical charge through stress generated potentials in the canaliculi, and piezoelectricity of the collagen-hydroxyapatite junctions. External electrical stimulation (ES) has been shown to increase bone formation, indicating that the cells involved in remodelling are electrically sensitive. However, the effects of ES on osteocytes specifically are under-researched. Before applying ES in vitro the electrical characteristics of the culture media need to be understood to see if it will negatively impact cells in culture. ES in culture media causes pH changes and gas formation as well as precipitate formation directly on the electrode surface. The resistance of the media increases rapidly upon application of the electrical stimulus and plateaus after 100 - 200 minutes. The pH gradient disperses around the same time frame, with most stimulating currents causing no permanent change to the media pH. Stimulation parameters that cause minimal side effects will be better for the health of cells in culture. This should also make it more clear which outcomes are a result of the electrical stimulation and which come from the electrochemical reactions that are present in the media due to the ES.