Bromochloroacetonitrile Cytotoxicity and Regenerative Responses in HaCaT and HUVEC Cells

Bromochloroacetonitrile (BCAN) is a halogenated nitrogenous disinfection byproduct (N-DBP) frequently detected in chlorinated swimming pools. While its cytotoxicity has been established in various mammalian cells, its dermal and vascular impacts remain poorly understood. This study evaluated the cytotoxic, oxidative, and regenerative responses of human keratinocytes (HaCaT) and vascular endothelial cells (HUVECs) to BCAN exposure in vitro. BCAN significantly reduced HaCaT viability in a concentration- and time-dependent manner, with an IC₅₀ of ∼42 μM at 48 h. Increased lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) generation confirmed membrane damage and oxidative stress. In contrast, HUVECs maintained viability and membrane integrity at all concentrations except 80 μM, indicating higher cellular resilience. Representative scratch and tube formation assays suggested that keratinocyte migration and endothelial angiogenic behavior were largely preserved, with only moderate impairment at cytotoxic concentrations. These findings highlight the selective sensitivity of skin cells to BCAN and suggest that short-term BCAN exposure may have limited effects on wound closure- and angiogenesis-related responses under the present experimental conditions. The results underscore the importance of evaluating regenerative end points in the risk assessment of unregulated DBPs in recreational waters.