Synthesis of magnetic microtubes decorated with nanowires and cells

Antiferromagnetic and ferrimagnetic microtubes decorated with nanowires have been obtained during thermal oxidation process, which was assisted by in situ electrical resistivity measurements. The synthesis route including heat treatment and electrical current along with growth mechanism are presented. This simple method and the ability to tune in the magnetic moment of the obtained microtubes going from a nonmagnetic-like to a large magnetization saturation open an avenue for interesting applications. In vitro experiments involving adherence, migration, and proliferation of fibroblasts cell culture on the surface of the microtubes indicated the absence of cytotoxicity for this material. We have also calculated both torque and driving magnetic force for these microtubes with nanowires and cells as a function of external magnetic field gradient which were found to be robust opening the possibility for magnetic bio micro-robot device fabrication and application in biotechnology.