@article{agbodjan_khaledi_2003, title={Study of solute partitioning into cationic vesicles of dihexadecyldimethylammonium bromide using electrokinetic chromatography}, volume={1004}, ISSN={["0021-9673"]}, DOI={10.1016/S0021-9673(03)00853-7}, abstractNote={A cationic vesicular pseudo-stationary phase was used in electrokinetic chromatography. The stable cationic lipid bilayer, composed of a double chain cationic surfactant, dihexadecyldimethylammonium bromide was prepared in deionized water, with no buffer additive. The chromatographic characteristics of this novel pseudo-phase are presented. A linear solvation energy relationship was successfully used to characterize the interaction of neutral solutes with the cationic vesicles. This study was complemented by the determination of changes in the free energy for transfer of various groups from the aqueous phase into the bilayer.}, number={1-2}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Agbodjan, AA and Khaledi, MG}, year={2003}, month={Jul}, pages={145–153} } @article{burns_agbodjan_khaledi_2002, title={Characterization of solvation properties of lipid bilayer membranes in liposome electrokinetic chromatography}, volume={973}, ISSN={["0021-9673"]}, DOI={10.1016/S0021-9673(02)00955-X}, abstractNote={The nature of solute interactions with biomembrane-like liposomes, made of naturally occurring phospholipids and cholesterol, was characterized using electrokinetic chromatography (EKC). Liposomes were used as a pseudo-stationary phase in EKC that provided sites of interactions for uncharged solutes. The retention factors of uncharged solutes in liposome EKC are directly proportional to their liposome-water partition coefficients. Linear solvation energy relationship (LSER) models were developed to unravel the contributions from various types of interactions for solute partitioning into liposomes. Size and hydrogen bond acceptor strength of solutes are the main factors that determine partitioning into lipid bilayers. This falls within the general behavior of solute partitioning from an aqueous into organic phases such as octanol and micelles. However, there exist subtle differences in the solvation properties of liposomes as compared to those of octanol and various micellar pseudo-phases such as aggregates of sodium dodecyl sulfate (SDS), sodium cholate (SC), and tetradecylammonium bromide (TTAB). Among these phases, the SDS micelles are the least similar to the liposomes, while octanol, SC, and TTAB micelles exhibit closer solvation properties. Subsequently, higher correlations are observed between partitioning into liposomes and the latter three phases than that into SDS.}, number={1-2}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Burns, ST and Agbodjan, AA and Khaledi, MG}, year={2002}, month={Oct}, pages={167–176} } @article{agbodjan_bui_khaledi_2001, title={Study of solute partitioning in biomembrane-mimetic pseudophases by electrokinetic chromatography: Dihexadecyl phosphate small unilamellar vesicles}, volume={17}, ISSN={["0743-7463"]}, DOI={10.1021/la001120n}, abstractNote={Solute partitioning into vesicles of dihexadecyl hydrogen phosphate (DHP) was investigated by electrokinetic chromatography (EKC). The ionic double-chain surfactant forms bilayer structures that mimic a biological membrane when dispersed in aqueous media. The linear solvation energy relationship (LSER) was used to gain insights about the nature of interactions and parameters that influence the partitioning process into vesicles, micelles, and n-octanol. The Gibbs free energies of transfer of selected functional groups from aqueous to vesicular phases were compared to those in micellar pseudophases of sodium dodecyl sulfate (SDS) and sodium dodecyl phosphate (SDP). Size and hydrogen bond acceptor strength of solutes are the main factors that determine their partitioning behavior, while dipolarity and polarizability play minor, yet significant, roles. It was determined that the cohesiveness of solute microenvironments in DHP vesicles is between those for micells and n-octanol. Vesicles are weaker hydrogen b...}, number={10}, journal={LANGMUIR}, author={Agbodjan, AA and Bui, H and Khaledi, MG}, year={2001}, month={May}, pages={2893–2899} }