Enantioselective Partitioning of Polychlorinated Biphenyls in a HepG2 Cell Culture System: Experimental and Modeling Results

We investigated the partitioning of chiral PCBs (PCB 91, PCB 95, PCB 132, or PCB 136) in the human hepatoma HepG2 cell line and used a computational model for the in vitro to in vivo extrapolation (IVIVE) of PCB levels. HepG2 cells were incubated with PCBs for 72 h. PCB levels were quantified in cells, media, and cell culture dishes. PCBs were present in cell culture medium > cells > dishes, and displayed atropisomeric enrichment in cells and dishes. The free PCB concentration in media, estimated using polyparameters linear free energy relationships (PP-LFERs) and a composition-based model, was used to extrapolate from the nominal PCB concentration used in vitro to PCB tissue levels and vice versa. This approach allows for an IVIVE but does not account for the atropselective partitioning of chiral PCBs between medium and cells.