The Behaviour of Neuro-2A Cells on Silicon Substrates with Various Topographies Generated by Femtosecond Laser Micromachining

The interaction of neural cells with silicon surfaces is important for basic research as well as for various possible applications, such as silicon-based neural implants and neurochips. Laser structuring of silicon provides a quick and versatile method for the generation of complex, hierarchical topographies on precise locations of the substrate. The behaviour ofNeuro-2A cells with laser-structured silicon substrates was studied using a live-imaging setup with fluorescence microscopy. Neuro-2A cells were able to adhere to polished silicon, ripples and microcolumns to different extents, depending on the substrate topography and incubation time. Initially, cells adhere much better to structured areas, resulting in visible cell patterning on the substrates. Time-lapse microscopy revealed cell exploration and motility behaviours on the substrates. Cell motility was significantly decreased on structured substrates, with whole area microcolumns having the slowest cell motility. On polished silicon, cells were found to interact with the substrates using lamellipodia and filopodia. After 24 or 48 hours, cells were better able to adhere to polished as well as structured silicon. Neurite alignment xl.as observed on microcolumn and trench substrates. On the other hand, highly processed substrates were inhibitory to cell growth and resulted in poor cell health.