Interaction of B50 rat hippocampal cells with stain-etched porous silicon

We present a scanning electron microscopy study of interaction of porous silicon prepared by stain etching with rat hippocampal neurons (B50, immortalised line). Porous Si has been prepared by stain etching both from crystalline and polycrystalline substrates. Two types of patterns have been examined: (i) 100 microm square pads separated by 100 microm of untreated space and (ii) 30 microm and 100 microm stripes separated by 300 microm of untreated surface. In all cases cells show clear preference in adhesion to porous Si over untreated surface. We observe a much closer attachment of the cell to the surface of porous Si than has been anticipated before with the gap between a cell and porous surface of no more than 20 nm. This study demonstrates the influence of surface topology on proliferation of a neuron network, thus suggesting that a degree of control over cell growth pattern can be achieved using porous material alone. We show that the network pattern on porous Si is influenced by a single neuron response to the surface nature and topology.