Magnetic tissue engineering of the vocal fold using superparamagnetic iron oxide nanoparticles.

Losing one`s ability to speak, due to tissue deficiency at the vocal fold (VF), leads to serious impairment in the quality of life. Until now, there is no successful approach for regenerating the VF. The aim of this work is to show the advantage of magnetic nanoparticles in the generation of scaffold-free 3D VF cell-constructs via magnetic tissue engineering (MTE). Rabbit VF-fibroblasts were used to establish MTE: after cellular uptake of superparamagnetic iron oxide nanoparticles (SPIONs), cells can be controlled with a magnetic field thereby forming solid 3D cell-structures. To transfer this method into human cells, SPIONs were adapted accordingly and tested for their influence on human VF-cells and for their ability to perform MTE with human VF-cells. Interestingly, the cell number and the magnet's shape influence the form of the rabbit-VF cell-construct. After successful characterization of human VF cells, biocompatibility analyses revealed no significant influence of SPIONs on them, thus 3D human VF cell-constructs could be successfully generated via MTE. These basic results are important to develop MTE as an innovative method to regenerate functional VFs. We expect that in vivo studies, including MTE as an elegant, far-field controlled and touchless technology, will translate MTE-VF bio-constructs into reconstructive laryngeal medicine.