Magnetic tissue engineering of human vocal fold fibroblasts using superparamagnetic iron oxide nanoparticles

In tissue engineering, regenerative medicine attempts to artificially recreate tissues or even organs to replace them in patients. Vocal folds in the larynx are crucial structures for voice production. In vitro reconstruction of a damaged vocal fold is, however, complicated as it has a complex structure with different specialized cell types, whose arrangement in the tissue is crucial for the formation of extracellular matrix (ECM) and its function. In order to precisely arrange human vocal fold fibroblasts (VFF) in cell culture, they were functionalized with superparamagnetic iron oxide nanoparticles (SPIONs) to enable their magnetic controllability ("magnetic tissue engineering"). Depending on the cellular amount of SPIONs, VFF cells could be magnetically positioned at the exact location determined by simulation of the magnetic field. In 3-dimensional cell constructs grown from VFF, various ECM proteins could be detected. In order to selectively arrange cells within a spheroid ("magnetic micro-patterning"), loaded and unloaded fluorescence-labeled cells were co-incubated under the influence of a magnetic field. Fluorescence microscopy revealed a Janus-like structure with loaded VFF cells facing the magnetic field and the unloaded cells on the opposite side. Next, we want to magnetically steer vocal fold epithelial cells to the desired position of the construct and grow there. The micro-structuring will be optimized with further cell types to enable a patient-oriented therapy in the future.