Myotube orientation using strong static magnetic fields

Abstract

In this experiment, we evaluated the effects of strong static magnetic fields (SMF) on the orientation of myotubes formed from a mouse-derived myoblast cell line, C2C12. Myogenic differentiation of C2C12 cells was conducted under exposure to SMF at a magnetic flux density of 0-10 T and a magnetic gradient of 0-41.7 T/m. Exposure to SMF at 10 T led to significant formation of oriented myotubes. Under the high magnetic field gradient and a high value of the product of the magnetic flux density and magnetic field gradient, myotube orientation increased as the myogenic differentiation period increased. At the 3 T exposure position, where there was a moderate magnetic flux density and moderate magnetic field gradient, myotube orientation was not observed. We demonstrated that SMF induced the formation of oriented myotubes depending on the magnetic flux density, and that a high magnetic field gradient and a high value of the product of the magnetic flux density and magnetic field gradient induced the formation of oriented myotubes 6 days after myogenic differentiation. We did not detect any effect of the static magnetic fields on myogenic differentiation or cell number. To the best of our knowledge, this is the first report to demonstrate that myotubes orient to each other under a SMF without affecting the cell number and myogenic differentiation.

Biologic-free mechanically induced muscle regeneration

“…Although additional biomaterial-based approaches have induced similar improvements in muscle function through the codelivery of myogenic bioagents with endothelial cells to enhance vascularization (5.5-fold increase in active stress over blank scaffold) or neural stem cells to promote innervation of muscle constructs (2.0-fold increase in maximum tetanic force over nerve-deficient controls) (44)(45)(46)(47), no bioagents were delivered from the scaffolds in this study. It is possible that the magnetic field directly affected regeneration in the current study, as past studies involving treatment of myoblasts and myotubes with static magnetic fields have demonstrated increased myogenic differentiation and cell alignment (48,49). However, although a slight increase in peak tetanic force was observed with magnetic field application in the current study, results were not significantly different from the untreated controls, perhaps because of the relatively short duration of magnetic field exposure.…”

Use of Magnetic Forces to Promote Stem Cell Aggregation During Differentiation, and Cartilage Tissue Modeling

“…One important issue is the possible direct impact of this magnetic field on MSC differentiation. Indeed, some studies have suggested an influence of static and alternating magnetic fields on the functions of neurons,18 myotubes,19 and stem cells 20. Osteogenesis, adipogenesis and chondrogenesis were thus investigated in the presence and absence of a 0.2‐T magnetic field, and no influence was observed on any of these three differentiation pathways (Figure S2).…”

Evaluation of the effect of static magnetic fields combined with human hepatocyte growth factor on human satellite cell cultures

“…Sakurai et al demonstrated that the exposure to strong SMF (10 T) led to significant numbers of orientated myotubes in cultures from the mouse-derived myoblast cell line (C2C12). No effect on differentiation was observed when 3 T was applied (13). Furthermore, Kim et al demonstrated that SMF (2 T) in C2C12 myoblast cells inhibits proliferation and may delay cell growth by altering the subcellular localization of gamma complex protein 3 (14).…”