title: Nanoparticle-supported lipid bilayers as an in situ remediation strategy for hydrophobic organic contaminants in soils.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental organic contaminants due to their low water solubility and strong sorption onto organic/mineral surfaces. Here, nanoparticle-supported lipid bilayers (NP-SLBs) made of 100-nm SiO2 nanoparticles and the zwitterionic lipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) are investigated as constructs for removing PAHs from contaminated sites, using benzo[a]pyrene (BaP) as an example. DMPC in the form of small unilamellar vesicles (SUVs) or DMPC-NP-SLBs with excess DMPC-SUVs to support colloidal stability, when added to saturated BaP solutions, sorb BaP in ratios of up to 10/1 to 5/1 lipid/BaP, over a 2-week period at 33 °C. This rate increases with temperature. The presence of humic acid (HA), as an analog of soil organic matter, does not affect the BaP uptake rate by DMPC-NP-SLBs and DMPC-SUVs, indicating preferential BaP sorption into the hydrophobic lipids. HA increases the zeta potential of these nanosystems, but does not disrupt their morphology, and enhances their colloidal stability. Studies with the common soil bacteria Pseudomonas aeruginosa demonstrate viability and growth using DMPC-NP-SLBs and DMPC-SUVs, with and without BaP, as their sole carbon source. Thus, NP-SLBs may be an effective method for remediation of PAHs, where the lipids provide both the method of extraction and stability for transport to the contaminant site.
authors.affiliation: Department of Chemistry and ‡Department of Earth and Environmental Science, Temple University , Philadelphia, Pennsylvania 19122, United States.
authors.forename: Hairong
authors.initials: H
authors.lastname: Wang
authors.forename: Bojeong
authors.initials: B
authors.lastname: Kim
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Wunder
mesh_terms: D001673:Biodegradation, Environmental; D002152:Calorimetry, Differential Scanning; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006812:Humic Substances / Q000032:analysis; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D009930:Organic Chemicals / Q000302:isolation & purification*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011549:Pseudomonas / Q000254:growth & development; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000302:isolation & purification*; D055672:Static Electricity; D013535:Suspensions; D013997:Time Factors
chemical_list: D006812:Humic Substances; D008051:Lipid Bilayers; D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D013535:Suspensions; D004134:Dimyristoylphosphatidylcholine