Remotely Controlled Mechanotransduction via Magnetic Nanoparticles: Applications for Injectable Cell Therapies.

INTRODUCTION: Bone requires dynamic mechanical stimulation to form and maintain functional tissue, yet mechanical stimuli are often lacking in many therapeutic approaches for bone regeneration. Magnetic nanoparticles provide a method for delivering these stimuli by directly targeting cell-surface mechanosensors and transducing forces from an external magnetic field, resulting in remotely controllable mechanotransduction. In this investigation, functionalised magnetic nanoparticles were attached to the mechanically-gated TREK-1 K+ channels of human mesenchymal stem cells1. These cells were microinjected into an ex vivo chick foetal femur (e11) as a model for endochondral bone formation2,3. An oscillating 25mT magnetic field was used to induce mechanotransduction in the injected MSCs via the nanoparticles. Further analysis was performed in vitro in both monolayer and 3D hydrogel cultures4.