Figure 2.

Polystyrene microspheres alter growth patterns in A549 cells. Cell number changes after polystyrene microsphere treatment across dose (0–30 µg/ml), UV-photoaging, size (1 or 5 µm), and time (24, 48, and 72 h). Relative to untreated controls, greater cell numbers were observed at all doses, sizes, and aging conditions (*P < .0001), except for the high dose (30 µg/ml) of the aged polystyrene microspheres (^†P < .01 compared with 10 µg/ml). Fresh polystyrene microspheres displayed an increasing trend even at 30 µg/ml, while photoaged microspheres reduced cell numbers to control (untreated) levels.