@article {4611,
	title = {A H-1-NMR study of the permeation of glycolic acid through phospholipid membranes},
	journal = {Biochimica Et Biophysica Acta-Biomembranes},
	volume = {1416},
	number = {1-2},
	year = {1999},
	note = {ISI Document Delivery No.: 162BFTimes Cited: 10Cited Reference Count: 31},
	month = {Jan},
	pages = {333-338},
	type = {Article},
	abstract = {The transmembrane permeability coefficient of the alpha-hydroxyacid, glycolic acid, has been measured for egg phosphatidylcholine large unilamellar vesicles. The determination of the vesicle concentration independent first-order rate constant for membrane transport and the permeability coefficient were made using an NMR technique employing shift agents. Both the temperature dependence and the dependence on cholesterol content were investigated. The activation energy and the Arrhenius pre-exponential factor were found to be dependent on the cholesterol content. A marked increase in both parameters was observed up to 20 mol\% cholesterol, with a further, small increase up to 50\%. The pH dependence of permeability was also investigated. An increase in permeability is observed with a decrease in pH, providing a possible explanation for the effectiveness of glycolic acid in skin treatment. (C) 1999 Published by Elsevier Science B.V. All rights reserved.},
	keywords = {ACETIC-ACID, acne, aging of the, BILAYER-MEMBRANES, CHOLESTEROL, CHOLESTEROL CONTENT, glycolic acid, H-1-NMR, HUMAN ERYTHROCYTES, LAIDLAWII-B-CELLS, LARGE UNILAMELLAR VESICLES, lipid, NONELECTROLYTE, NUCLEAR MAGNETIC-RESONANCE, permeability, SKIN, transmembrane permeability, TRANSPORT, WATER},
	isbn = {0005-2736},
	url = {<Go to ISI>://000078324700030},
	author = {Males, R. G. and Herring, F. G.}
}
@article {4210,
	title = {Inhibition of liposome-induced complement activation by incorporated poly(ethylene glycol) lipids},
	journal = {Archives of Biochemistry and Biophysics},
	volume = {357},
	number = {2},
	year = {1998},
	note = {ISI Document Delivery No.: 119UCTimes Cited: 65Cited Reference Count: 50},
	month = {Sep},
	pages = {185-194},
	type = {Article},
	abstract = {Complement activation causes opsonization of foreign particles leading to particle elimination from the blood. Complement-mediated opsonization of charged and large liposomes presents a fundamental problem in their use to deliver therapeutic agents in vivo. To prolong the circulation half-lives of such liposomes, complement activation must be curtailed. The aim of this study was to assess the ability of poly(ethylene glycol)-lipids (PEG-lipids) to inhibit the in vitro activation of the classical pathway of complement in human serum by anionic liposomes. Incorporation of cholesterol-PEG(600) (CH-PEG(600)), cholesterol-PEG(1000) (CH-PEG(1000)), or phosphatidylethanolamine-PEG(2000) (PE-PEG(2000)) resulted in dose-dependent inhibition of Clq binding and complement activation. The dose of PEG-lipid at which complement activation was blocked was inversely related to the PEG chain length. Complement activation was strongly inhibited when 15 mole\% of CH-PEG(600), 10 mole\% CH-PEG(1000), or 5 mole\% PE-PEG(2000), was incorporated into 100-nm anionic liposomes. PEG-lipid incorporation into larger liposomes (240 nm) was also successful in blocking C1q binding and complement activation. Radiolabeled cholesterol-PEG(similar to 1400) was prepared and used to determine both the percentage of CH-PEG incorporated into the liposomes and the percentage maintained in the liposomes in the presence of 50\% human serum at 37 degrees C for up to 24 h. (C) 1998 Academic Press.},
	keywords = {C1q, CHOLESTEROL, CLEARANCE, complement activation, HEPATIC-UPTAKE, INVIVO, LARGE UNILAMELLAR VESICLES, LIPOSOMES, POLY(ETHYLENE GLYCOL), POLYETHYLENE-GLYCOL, PROLONGED CIRCULATION TIME, SERUM, SIZE, SURFACE-CHARGE},
	isbn = {0003-9861},
	url = {<Go to ISI>://000075915200002},
	author = {Bradley, A. J. and Devine, D. V. and Ansell, S. M. and Janzen, J. and Brooks, D. E.}
}
@article {4345,
	title = {Vesicular membrane permeability of monomethylarsonic and dimethylarsinic acids},
	journal = {Biophysical Chemistry},
	volume = {70},
	number = {1},
	year = {1998},
	note = {ISI Document Delivery No.: YU539Times Cited: 6Cited Reference Count: 45},
	month = {Jan},
	pages = {75-85},
	type = {Article},
	abstract = {The transmembrane permeability coefficients of the environmentally sensitive arsenicals, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) have been measured for egg phosphatidylcholine large unilamellar vesicles. The determination of the vesicle concentration-independent first-order rate constants for membrane transport and the permeability coefficients were made using an NMR technique employing shift agents. The permeability coefficient of DMA was found to be two orders of magnitude greater than that of MMA. This is attributed to the presence of MMAs extra hydroxyl group. Both species are shown to permeate membranes in the neutral form. Both the temperature dependence and the dependence on cholesterol content were investigated for DMA. The activation energy and the Arrhenius preexponential factor were found to be dependent on the cholesterol content. A marked increase in both parameters was observed up to 20 mol.\% cholesterol, with a further, small increase up to 60\%, The significance of these results to our understanding of membrane transport is discussed. The importance of using permeability coefficients rather than n-octanol/water partition coefficients in determining bioavailability and bioaccumulation of environmentally sensitive compounds is also discussed. (C) 1998 Elsevier Science B.V.},
	keywords = {BILE-ACIDS, CHOLESTEROL, DIFFUSION, DIMETHYLARSINIC ACID, HUMAN-ERYTHROCYTES, LIPID BILAYER-MEMBRANES, monomethylarsonic acid, NONELECTROLYTE, nuclear magnetic resonance, PARTITION-COEFFICIENTS, permeability, phosphatidylcholine membranes, RAPID EXTRUSION PROCEDURE, TRANSPORT, UNILAMELLAR VESICLES},
	isbn = {0301-4622},
	url = {<Go to ISI>://000071728000008},
	author = {Males, R. G. and Nelson, J. C. and Phillips, P. S. and Cullen, W. R. and Herring, F. G.}
}
