Correlation of astroglial cell function on micro-patterned surfaces with specific geometric parameters

Microcontact printing techniques were used to modify silicon substrates with arrays of hexagonal features of N1[3-(trimethoxysilyl)propyl]diethylenetriamine (DETA) surrounded by octadecyltrichlorosilane (OTS), which are hydrophilic, cell-adhesive and hydrophobic, non-adhesive organosilanes, respectively. In the presence of serum proteins, LRM55 cell adhesion and morphology on these modified surfaces were best correlated to the width of the cell-adhesive features. On surfaces modified with small (5 μm in width) cell-adhesive features, LRM55 cells elaborated only thin processes. As feature width was increased, cells on these surfaces exhibited increased cell spreading and elaborated wide processes. On surfaces modified with large (>35 μm in width) features, single cells adhered to and spread upon individual DETA features. In a similar fashion, LRM55 cell adhesion density increased with increasing feature width; this correlation could be represented by a simple, second-order relation, and was independent of all other measures of pattern geometry. The results of this study provide evidence that micro-patterning may be effective in controlling astrocyte interaction with implant materials.