Selective Adhesion of Astroglial Cells to Lithographically-Defined Reactive Ion Etch (LRIE) Surfaces
LRIE Fabrication Technique
Silicon wafer substrates were modified by reactive ion etching, using a photolithographically patterned layer of silicon oxide as an etch mask. The resultant surfaces contained arrays of cylindrical features, spaced 1.5 µm apart. By varying the etch duration, two series of surfaces, containing different feature dimensions, were fabricated onto silicon wafer substrates.
Cell Adhesion Results
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In the presence of serum proteins, LRM55 cells and primary cortical astrocytes preferentially adhered to silicon patterned with arrays of 1 µm tall, 400-nm diameter cylindrical features (series A, above) compared to unpatterned silicon. LRM55 cells, but not primary cortical astrocytes, preferentially adhered to arrays of 2 µm tall, 650-nm diameter features (series B). Features in arrays are spaced 1.5 µm apart (center to center). In the fluorescence images, cell membranes have been stained with cyanine dye and appear red. Reflectance images, indicative of bars of LRIE-induced features, are presented in register with the cyanine dye stain.
Selective Establishment of Focal Contacts
In the presence of serum proteins, LRM55 cells establish focal contacts (punctate formations of vinculin indicated by blue arrows) with non-LRIE-textured silicon. On regions or LRIE-textured silicon, vinculin staining is diffuse or limited to small formations. Fluorescence image of sample stained for vinculin (red) and tubulin (green), is overlayed with a reflectance image (grey) which identifies a bar of LRIE-etched silicon.
Last modified 7 April 1998