Microscope images of cell cultures with alveolar type 2 cells from rat. Figure a shows cells just before exposure to 1 mM HEMA. Figure b shows an image of the same area in the cell culture after six hours. The arrows show morphological changes in the cells associated with apoptotic cell death (nuclear condensation and fragmentation of the cell).
Resin-based dental materials are commonly polymerized in place, hence dental personnel handle uncured materials on a daily basis. The reactive methacrylate monomers are one main component of these materials and levels are detected even in the air at dental clinics. Exposure through the airways may therefore be of importance as an occupational exposure route.
In a recent study using primary epithelial lung cells, the commonly used methacrylate 2-hydroxyethyl methacrylate induced cell death (arrows undicating dead cells in picture above). Nuclear condensation was evident in the majority of cells after only six hours. This effect was effectively counteracted both by an antioxidant and a specific inhibitor of the cytochrome P450 (CYP) 2E1 enzyme. A biotransformation reaction of HEMA to a highly reactive intermediate is suggested to be responsible for this severe response.
The work has been published in Journal of Biomedical Materials Research Part A.