Artikel
Co-culture with human osteoblasts and exposure to extremely low-frequency pulsed electromagnetic fields improve osteogenic differentiation of human adipose derived mesenchymal stem cells
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Veröffentlicht: | 6. November 2018 |
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Gliederung
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Objectives: Human adipose-derived mesenchymal stem/stroma cells (Ad-MSCs) have been proposed as suitable option for cell based therapies to support bone regeneration. In the bone environment Ad-MSCs will receive stimuli from resident cells that may favor their osteogenic differentiation. There is recent evidence that this process can be further improved by extremely low frequency pulsed electromagnetic fields (ELF-PEMFs). Thus the project aimed at (i) investigating whether co-culture of human osteoblasts (OBs) and Ad-MSCs favors their proliferation and osteogenic differentiation; (ii) whether this effect can be further improved by repetitive exposure to two specific ELF-PEMFs (16 and 26 Hz); (iii) and the effect of these ELF-PEMFs on human osteoclasts (OCs).
Methods: OBs and Ad-MSCs were isolated from human tissue by collagenase digestion. OCs were generated from peripheral blood mononuclear cells. During osteogenic differentiation cells were exposed to ELF-PEMFs with fundamental frequencies of 16 Hz or 26 Hz (Somagen®, Sachtleben GmbH) 7 min daily. Viability was assessed by mitochondrial activity and total protein content. OBs function was determined by AP activity and matrix mineralization. OCs function was determined by Trap5B activity. Data sets were compared by Kruskall Wallis test followed by Dunn?s multiple comparison test.
Results and conclusion: Osteogenic differentiation was improved by co-culturing OBs and Ad-MSCs when compared to the individual mono-cultures. An OBs to Ad-MSCs ratio of 3:1 had best effects on mitochondrial activity, total protein content, AP activity and matrix mineralization. Osteogenic differentiation was further improved by repetitive exposure to both ELF-PEMFs investigated, as can be observed in increased AP activity and matrix mineralization.
Figure 1 [Fig. 1]
Interestingly, only repetitive exposure to 26 Hz ELF-PEMF increased Trap5B activity in OCs. Considering this result, a treatment with gradually increasing frequency might be of interest, as the lower frequency (16 Hz) could enhance bone formation, while the higher frequency (26 Hz) could enhance bone remodeling.