Figure 1.

Estimation of optimal doses of TMZ and PT-PBS (kINPen) alone and in combination, for the cytotoxicity of glioblastoma multiforme (GBM) cells in 2D monolayers. We measured the cell cytotoxicity at different doses of (a) PT-PBS (the values in the x-axis are in %) and (b) TMZ, on U251, LN18 and LN229 (TMZ-sensitive) and U87-MG and T98G (TMZ-resistant) cell lines after 24 h incubation. We also determined the half maximal inhibitory concentration (IC₅₀) values of (c) PT-PBS and (d) TMZ on U251, LN18 and LN229 (TMZ-sensitive) and U87-MG and T98G (TMZ-resistant) cell lines. We analyzed the cell viability at a fixed dose of PT-PBS (10%), and varying doses of TMZ (i.e., 40 µM, 20 µM and 10 µM) alone and in combination, for TMZ-sensitive cells, i.e., (e) U251, (f) LN18, and (g) LN229, as well as for PT-PBS (at 15 or 20%) and varying doses of TMZ (i.e., 72 µM, 36 µM and 18 µM) alone and in combination, for TMZ-resistant cells, i.e., (h) U87-MG and (i) T98G, after 24 h incubation. The results are derived from three independent biological replicates and are shown as the mean ± standard error of the mean (SEM). Statistical analysis was performed by one-way analysis of variance (ANOVA) with Tukey’s comparison analysis. Statistically significant differences were found between the untreated control and corresponding treated samples. * = p ≤ 0.05; ** = p ≤ 0.01; *** = p ≤ 0.001, ns = not significant. PT-PBS: plasma-treated phosphate buffered saline, TMZ: Temozolomide.