Figure 1.

Cigarette smoke extract (CSE) exposure inhibited the viability and proliferation of primary human chondrocytes. Cells (N = 3, n = 3) were cultured in medium containing 0%, 0.1%, 0.5%, 1%, 5%, and 10% CSE. On day 1, 3, 7, and 14 chondrocytes (a) mitochondrial activity was determined by Resazurin conversion and (b) total protein content was determined by sulforhodamine B (SRB) staining, respectively. (c) Calcein-AM (green) and Hoechst 33,342 (blue) were used to show living cells on day 7, respectively. Results are presented as mean ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.001 as compared to untreated controls.