Calorimetric evaluation of interaction and absorption of polychlorinated biphenyls by biomembrane models

Polychlorinated biphenyls (PCBs) are organic pollutants with lipophilic properties, due to their persistence,they are present in environment at potentially dangerous concentrations for humans health. In this workwe investigated the interaction and absorption of 2,4,40-trichlorobiphenyl (PCB 28), 2,3,30,4,40-pentachlorobiphenyl(PCB 105) and 2,3,30,4,40,5,50-eptachlorobiphenyl (PCB 189) with dimyristoylphosphatidylcholine(DMPC) multilamellar vesicles (MLV), chosen as biomembrane models, by differential scanningcalorimetry technique (DSC). The obtained results indicate that the tested compounds affected thethermotropic behaviour of MLV to different degree, modifying the phase transition peak and shifting ittowards lower temperature. The effect of an aqueous or lipophilic medium on the absorption process ofthese compounds by the biomembrane models was also investigated revealing that the process is hinderedby the aqueous medium but favoured by the lipophilic medium.