Conventional lipid bilayer liposomes have similar inner and outer leaflet compositions; asymmetric liposomes have different lipid leaflet compositions. The goal of this work is to place cationic lipids in the inner leaflet to encapsulate negatively charged polynucleotides and to place neutral/anionic lipids on the outer leaflet to decrease nonspecific cellular uptake/toxicity. Inverse emulsion particles have been developed with a single lipid leaflet of cationic and neutral lipids surrounding an aqueous core containing a negatively charged 21-mer DNA oligo. The particles are accelerated through an oil-water interface, entrapping a second neutral lipid to form oligo encapsulated unilamellar liposome nanoparticles. Inverse emulsion particles can be consistently produced to encapsulate an aqueous environment containing negatively charged oligo. The efficiency of encapsulated liposome formation is low and depends on the hydrocarbon used as the oil phase. Dodecane, mineral oil, and squalene were tested, and squalene, a branched hydrocarbon, yielded the highest efficiency.

Enhanced solubilization of dense nonaqueous phase liquids (DNAPLs) especially chlorinated hydrocarbons using four types of surfactants was investigated. The solubilization kinetics of perchloroethylene PCE (100 mg/L solubility in water) and trichloroethylene TCE (1000 mg/L) in anionic (sodium dodecyl sulfate (SDS)), nonionic (Triton X-100), cationic (cetyltrimethylammonium bromide (CTAB)), and a biosurfactant (UH biosurfactant) were investigated at room temperature in continuously stirred batch reactors. The size distribution of surfactant micelles were measured using the dynamic light scattering device (DLS). The mean size of SDS, CTAB, Triton X-100, and UH biosurfactant micelles were 4.2 nm, 3.8 nm, 4.5 nm, and 59.1 nm, respectively. Micelle partition coefficients (Km) and molar solubility ratio (MSR) for PCE and TCE in 10 g/L of surfactant solutions have been quantified, and the solubility of PCE and TCE in the surfactant solutions increased by about 10-fold. Solubilization kinetics for PCE and TCE in various surfactant solutions was represented using a hyperbolic relationship. Also the relationship between solubility and interfacial surface tension reduction was investigated. Of the surfactants studied, Triton X-100 had the highest PCE solubilized per gram of surfactant, whereas for TCE, biosurfactant had the highest TCE solubility per gram of surfactant.

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