Modulative effects of carbon black and polyethylene micro-nanoplastic particles on blood-brain barrier model invitro

Microplastics (MP) and nanoplastics (NP), including low-density polyethylene (LDPE), as well as carbon-based particles such as carbon black (CBP) and black carbon (BC) from incomplete combustion, are widespread environmental pollutants. Their co-occurrence in airborne particulate matter raises concerns about potential impacts on sensitive barriers such as the blood-brain barrier (BBB). This study investigates the effects of CBP and LDPE particles on human cerebral microvascular endothelium hCMEC/D3 cells, an in vitro BBB model. Using a stable NRF2 reporter cell line, we assessed barrier function via transendothelial electrical resistance (TEER), particle uptake through confocal microscopy, and morphological changes using CellProfiler. Inflammatory and oxidative stress responses were also evaluated. CBP exposure increased TEER values, suggesting an occluding effect on barrier integrity. Additionally, CBP enhanced phagocytic activity and reduced IL-1β levels, indicating modulation of inflammation. In contrast, although internalized by cells, LDPE particles had minimal impact on morphology, phagocytosis, inflammation, or barrier function. These findings offer new insights into the cellular responses to airborne pollutants, highlighting the differential effects of CBP and LDPE particles on the BBB and underscoring the need for further studies on their combined impact.