Magnetic field application or mechanical stimulation viamagnetic microparticles does not enhance chondrogenesis in mesenchymal stem cell sheetsElectronic supplementary information (ESI) available: Modeling of forces on a magnetic particle; data from supplementary experiments of hMSC sheets without and with magnetic particles stimulated by magnetic fields. See DOI: 10.1039/c7bm00061h

Using a novel magnetic field bioreactor, this work evaluated the chondrogenesis of scaffold-free human mesenchymal stem cell sheets in response to static and variable magnetic fields, as well as mechanical stimulation via4.4 μm magnetic particles. Neither static nor variable magnetic fields generated by 1.44–1.45 T permanent magnets affected cartilage formation. Notably, magnetic field-induced mechanical stimulation by magnetic particles, which applied forces to the cells and ECM statically (4.39 pN) or cyclically (1.06–63.6 pN; 16.7 mHz), also did not affect cartilage formation.