Kathrin Badstübner, Marco Stubbe, Thomas Kröger, Eilhard Mix and Jan Gimsa
/Ir) electrodes are substantially more stable, even though electrochemical byproducts of electrode processes may influence the surrounding tissue.
Electrical impedance spectroscopy is a common, nondestructive technique for determining the electrical properties of tissues [ 29 ]. It is used in a wide range of medical applications, such as breast-cancer detection [ 30 ], lung volume monitoring [ 31 ], and heart ischemia during surgery [ 32 ]. Impedance spectroscopy is also suitable for the characterization of DBS electrodes [ 26 ] and the encapsulation process of DBS electrodes
mechanotransduction are explored using viable artificial tissue-engineered skin in the form of an alginate encapsulated fibroblast. The artificial skin, which is considered to be a model system, is kept viable via a bespoke microfluidic system with integrated coplanar impedance sensors. Accurate normal loads are applied to the exposed surface of the artificial skin via indentation at small and large strains and the impedance monitored in real-time at a fixed single frequency. The fabrication of the microfluidic system and impedance sensors is described. The electrical properties of
The paper presents a micro encapsulation method of α-Fe2O3 nanoparticles in PEG4000. A suspension of α-Fe2O3 nanoparticles and dissolved PEG is sprayed through a nozzle at atmospheric pressure. After rapid expansion, core-shell composite microparticles that don´t tend to agglomerate are obtained. Structure and morphology were investigated by electronic microscopy (TEM and SEM), X-ray diffraction (XRD), and spectral technique (UV-Vis and FTIR).
consists of two electrodes placed in parallel of area 4 cm2 each. The screw enables variation of the distance between the electrodes from 0 to 10 cm with an accuracy of approximately 0.5 mm. The reason for vertical placement of the electrodes was that with this approach we minimized the problems associated with liquid leakage and sealing.
A suspension of microcapsules was used as a medium. Microencapsulations are frequently used in pharmaceutical industries for encapsulation of drugs. The paraffin microcapsules are of interest in particular for their ability to store
removed from this native three- dimensional environment (3D) and limited to a monolayer (2D), cells would show unnatural behavior ( 48 , 49 ). Due to the resemblance to in vivo situations and the ability to provide a physiologically relevant environment, three-dimensional (3D) cell cultures have been developed ( 48 , 55 ). To mimic the in vivo environment, cells are encapsulated within 3D scaffolds ( 56 ), where the properties of the scaffolds such as stiffness, composition and porosity have an important influence on cell physiology ( 57 , 58 , 59 ).
.95) through a range of compression levels ( Fig. 5 and 6 ) resulting in a mechanical model of tofu (Eq. (9)); (3) the behavior of normalized admittance correlating well with initial strain level, resulting from a simple constant relationship with the stress relaxation curve ( Fig. 9 Fig. 12 ); and (4) a final physical model of tofu encapsulating both mechanical and passive electrical properties ( Fig. 13 and Eq. 18). This culmination of facts shows that tofu is capable of testing the predictions made by researchers about the effects of pressure and force on measured