Figure 5.

Viability and proliferation characteristics of Human 1321N1 astroglial cells on pentacene thin films. Cells were incubated for up to 48 h on pentacene films of varied thickness and tested by the Trypan blue exclusion test. (a) The three-dimensional graph showing density of viable cells/mm², versus thickness Θ (in ML) and incubation time (h). Maximum is for thicknesses <10 ML (respectively at 12 h, P = 0.006 and 0.035, 1.5 ML and 4 ML vs. 65 ML; at 24 h, P = 0.033 and 0.047 for 1.5 ML and 4 ML vs. 65 ML; at 48 h, P = 0.049 and 0.032 for 1.5 ML and 4 ML vs. 65 ML; Student's t-test, two-tailed, unpaired). The adhesion data at 3 h incubation in a serum-free medium has also been added. (b) Cell proliferation reported as the % of viable attached cells (with respect to seeded cells) versus time, for different Θ values: 4 ML (squares), 27 ML (triangles), and 65 ML (circles) The data at 3 h have been included. The solid line is the exponential fit using the equation: Viable cell %(t) = viable cell %(∞) − A exp(−t/τ). Inset: characteristic timescale, τ, versus Θ.