The investigation of cells in 3D, nontransparent scaffolds for bioengineering applications is a time consuming task. The main reason for this drawback is that up to now the cell distribution inside such a scaffold can be determined only by destructive methods like micro sectioning.
To overcome this drawback, we want to introduce a new localization method for cells that are labeled with magnetic nanoparticles. For this method we are using highly sensitive magnetoelectric (ME) sensors. These ME sensors, consisting of magnetostrictive and piezoelectric layers on a cantilever, show very high sensitivity, anisotropy and sharp mechanical resonance. Therefore, it is possible to detect very small AC magnetic fields at the resonance frequency of the sensor. By accurate measurements of the magnetic field generated by the magnetically labeled cells we want to determine the distribution of the cells in the bulk of the scaffold non-destructively.
Labelling the cells with appropriate particles is essential for this application. These particles must be superparamagnetic, biocompatible and the number of particles per cell has to be large, to generate a sufficiently high magnetic field.
Here, we investigate the biocompatibility of polymer-coated magnetic nanoparticles and their influence on the cell behavior as well as their storage limit per cell. Another point we have to take into account is the particle distribution after cell division. In the ideal case the particles would be distributed equally among the daughter cells but still the amount of particles per cell and therefor the magnetic field decreases. We will present strategies to counteract this effect, for example how a multistep labeling methods affect the distribution of particles absorbed per cell.