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Development of nanoelectrodes for cell stimulation and reduced foreign body reaction

: Weigel, Tobias; Schmitz, T.; Jannasch, Maren; Gätzner, S.; Walles, Heike; Hansmann, Jan

Bionanomaterials 15 (2014), Nr.S1, S.S162
ISSN: 2193-0651
ISSN: 2193-066X
Deutsche Gesellschaft für Biomaterialien (DGBM Jahrestagung) <2014, Dresden>
Fraunhofer IGB ()

A central challenge of current pacemakers is the high energy consumption caused by inefficient electrical stimulation of the cardiomyocytes. Reasons for this are leakage currents, the distance between electrode and target cells as well as the encapsulation of the electrode through the foreign body reaction (FBR).
In our study, different nanostructured electrodes are developed to minimize the energy loss at the interface between electrode and tissue/cell. Therefore needle-structured surfaces, as well as conductive electrospun scaffolds are generated. By functionalization of the surfaces with proteins or nanotubes, the cell material interaction is controlled. Aim of the project is to identify an ideal electrode configuration that provides direct cell contact and a reduced FBR.
Materials and Methods:
The needle-structures were fabricated by the vapor-liquid-solid (VLS) method using Low Pressure Chemical Vapor Deposition (LPCVD), SiH4 as precursor and gold nanoparticles as catalyst. The needle-structures were inspected by SEM.
The conductive fibers were generated by electrospinning a polyacrylonitrile (PAN) solution to either random or aligned fibre scaffolds. Through an oxidation step and subsequent carbonization the PAN fibers were converted to carbon fibers. This conversion was examined by FTIR- and Raman spectroscopy.
The electrodes were characterized by impedance spectroscopy and cyclovoltametry. The biocompatibility of different materials and nanostructures was measured by cytotoxicity tests. Additionally, the immunoreaction of THP-1 cells on the nanostructures was investigated through analyzing the released chemokines in the supernatant cell culture medium to characterize potential of an electrode to induce the FBR.
Results and Discussion / References:
As the next steps, the functionalization of the electrodes with proteins or nanotubes is planned to reduce the THP-1 reaction. Additionally, the electrode will be equipped with an in situ counter electrode by combination of the different nanostructures.