Fig. 7. Percentage of cells cultured on patterned and smooth substrates that had orientation angles less than 10° (designated aligned cells). On substrates with 600 nm deep grooves, the percentage of aligned cells was constant on patterns with pitches ranging from 400 nm to 2000 nm and decreased on 4000 nm pitch patterns. On 150 nm deep grooves, cell alignment was equivalent on all pattern pitches and was significantly lower than on 600 nm deep grooves, for pitches up to 2000 nm.