Applied nano bio systems with microfluidics and biosensors for three-dimensional cell culture

Applications of nanotechnology and microtechnology lead to a field which could be called nano-systems integration. The next step is the development of nanobiotechnological systems, which could reflect the hierarchical organization of biological systems that utilise scales and laws of nature on all metric scales. As one example of such systems we present the design and construction of a new class of micro bioreactors. It has been shown that 3D culture systems reveal the in vivo situation much better than the cultivation of 2D one cell type alone. For this purpose we have to construct and arrange fluidic devices and a cell-biological environment in such a way, that living cells can survive in a three-dimensional, organ-like structure, enabled by technical devices. Such organ-like cell structures may lead to new ways in medicinal chemistry for the determination of ADME/Tox (absorption-distribution-metabolism-excretion and toxicity) properties of potential drugs. One part of the construction principle is the integration of sensors, preferable novel AlGaN/GaN nanosensors. The latter nanosensors offer the possibility to estimate reactions of cells attached to the sensor surface non-destructively and label-free. These sensors are highly sensitive and biocompatible to cells. Furthermore, they are transparent to enable microscopic and other optical observations of the cells. In an advanced version the sensor is to be integrated to give a better insight into cellular processes of the cells that are cultivated in such micro bioreactors.