Study of neural cells on ultra thin organic film

Many technological advances are currently being adapted, nano- and micro- fabrication tools offer the ability to create and control patterns of materials with sub micrometric precision. Using stem assisted deposition techniques we succeeded in placing cells on the surface with precision in a culture system. Cells are grown under condition that facilitate survival and ideally promote their assembly into a rudimentary network of cells, but initial dispersion of cells is random and uncontrolled. Spatial patterning of cells can be helpful for the construction of the artificial circuits in environment, which is accessible for manipulation and study cell to cell and cell to environment interactions. This is important for construction of sensors and transducers. In this work we report the deposition of cells on organic semiconductor ultra-thin films. This is a first step towards the development of active bio/non bio systems for electrical transduction that could be integrated directly in vitro. Thin films of pentacene molecules, whose thickness was systematically varied between 1 and 50 nm, were grown by high vacuum sublimation. Human astrocytoma cells and NE-4C neural stem cells were grown and maintained in culture in standard conditions. Small molecules (PL, laminin, APTES, DDA, PEG etc.) were patterned onto the surface by template-assisted deposition in order to spatially modulate the cell adhesion on the surface. Released pre-patterned multilayers were exposed to cell culture medium incubated at 37oC for 70h. Viability of cells in time was measured as a function of roughness and the characteristic morphology of ultra thin organic film, as well as the features of the patterned molecules. Optical fluorescence microscope coupled to atomic force microscope in liquid was used to monitor the presence, density and shape of deposited cells. This work is supported by Project EU-NMP-STRP 032652 BIODOT.