Figure_1.jpg

A) Schematic representation of the experimental design to access the effects of different concentrations of lipopolysaccharides (LPS) on human dental pulp cells (HDPCs). Cells were tested under two different experimental conditions: #1) LPS concentrations diluted in FBS-free α-MEM (basal medium); or #2) LPS concentrations diluted in α-MEM + 10% FBS (growth medium). After 24 hours of cell seeding (Day 0), the culture media were supplemented or not with LPS (0 - control, 0.1, 1, and 10 µg/mL) for seven days. After this time interval, cell viability was evaluated, and cells were cultured in an odontogenic differentiation medium without LPS for further 21 days, when cell viability and mineralized matrix formation were evaluated. B) Schematic representation of the second experimental design. After 24 hours of cell seeding (Day 0), the culture medium was supplemented or not with LPS (0 - control, 0.1, 1, and 10 µg/mL) for seven days. After this time interval, cells were cultured in an odontogenic differentiation medium without LPS for up to 21 days. Cell viability was assessed weekly (from Day 1). On day 7, cells were also evaluated for NF-κB activation, gene expression, oxidative stress, and nitrite production. The formation of a mineralized matrix was evaluated after 14 and 21 days.