Effect Of Cyclodextrins On Mimic Bio-membrane Absorption Of Organic Chemicals

Organic pollutants will go directly or indirectly across the bio-membranes and cause harmful impacts to organisms. It is well recognized that bioavailability assessment of organic pollutants is necessary to predict their potential hazards. Cyclodextrins, as environment-friendly materials, have been applied to bioavailability assessments and thus bioremediation of organic pollutants. However, information related to the effects of cyclodextrins on bio-membrane adsorption of organic pollutants is rare. The PAMPA (Parallel Artificial Membrane Permeability Assay) is a more economical, easier and more efficient method than the traditional biological experiment. In this study, the parallel artificial membrane permeability assay (PAMPA) was carried out to assess the effects of hydroxypropyl-β-cyclodextrin (HP-β-CD) on bio-membrane adsorption of organic pollutants.A variety of types of organic pollutants (including pesticides, antibiotics, and transformation products) were included in this study. Both apparent permeability (Pa) and effective permeability (Pe) values of forty three chemicals were obtained. The latter was introduced to reconstitute the model of bioconcentration factors of organic pollutants on the whole fish base. Analysis the relationship between physicochemical properties (including Kow, Pa, Pe, etc.) and BCF of the whole fish was done. The results showed that the incorporation of Pe increased the correlation coefficient R2from0.788to0.861, making the better prediction potential of the BCF model.The effects of HP-β-CD concentrations on apparent permeability (Pa) and effective permeability (Pe) of these organic pollutants were investigated. The results showed that the Pa of fenamiphos sulfoxide increased in the presence of HP-P-CD while this parameter of the other42organic pollutants decreased. Based on inclusion equilibrium and mass balance, an equation of describing the effects of HP-β-CD concentrations on the apparent permeability (Pa) was developed, and the permeability (Pa-CD) of HP-β-CD-bound chemicals were calculated. The differences between the permeability potential of freely dissolved and HP-β-CD-bound organic pollutants predominantly account for the changes of the permeability of organic pollutants in the presence of HP-β-CD. The E. coli absorption experiments were conducted using four PAHs (i.e., naphthalene, acenaphthene, phenanthrene and anthracene) as model compounds, showing that the amounts of PAHs uptake are affected by the total dissolved amounts and permeability of these chemicals. An increase in the uptake was observed for the former two PAHs, as compared with an increase at first and then a decrease for the latter two.