Differential scanning calorimetry (DSC) and x-ray diffraction have been used to study the interaction of hydrated N-palmitoylgalactosylsphingosine (NPGS) and dipalmitoylphosphatidylcholine (DPPC). For mixtures containing less than 23 mol% NPGS, complete miscibility of NPGS into hydrated DPPC bilayers is observed in both the bilayer gel and liquid-crystal phases. X-ray diffraction data demonstra...

The interaction of the pulmonary surfactant protein SP-A fluorescently labeled with Texas Red (TR-SP-A) with monolayers of dipalmitoylphosphatidylcholine (DPPC) and DPPC/dipalmitoylphosphatidylglycerol 7:3 w/w has been investigated. The monolayers were spread on aqueous subphases containing TR-SP-A. TR-SP-A interacted with the monolayers of DPPC to accumulate at the boundary regions between liq...

In order to evaluate the usefulness of liposomes as oral vaccines, the stability of liposomes and serum IgA antibody response to antigen associated with liposomes after oral administration were examined. Liposomes composed of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylserine (DPPS), and cholesterol (Chol) (1:1:2, molar ratio), distearoylphosphatidylcholine (DSPC) and Chol (7:...

Infrared reflection-absorption spectroscopy (IRRAS) in combination with isotopic substitution and a modified 2D IR correlation analysis procedure were used to study the dynamics of phospholipid acyl chain structure in both an ideal and a nonideal binary monolayer mixture spread at the air-water (A/W) interface. The ideal mixture consisted of a 1:2 molar ratio of 1,2-dipalmitoyl-sn-glycero-3-pho...

The effect of aggregation of gramicidin A' (GA) on the phase structure of dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles was studied by cw-ESR using a chain-labeled lipid (16PC) at temperatures between 30 degrees and 45 degreesC that span the main phase transition of DPPC. Boundary lipids were observed only in dispersions with GA/DPPC molar ratios >1:15, where GA aggregates. Detai...

Phospholipase A2 (PLA2) is expressed in inflammation-related tissue, including cancer tumors. We report that a hybrid liposome composed of phospholipid (DPPC) and PEGylated block-copolymer (Poloxamer 188) can rapidly release an encapsulated hydrophilic drug in the presence of PLA2. DPPC/P188 liposomes released approximately 80% of the encapsulated calcein (a fluorescence marker) within 10min in...

We monitored the action of phospholipase A(2) (PLA(2)) on L- and D-dipalmitoyl-phosphatidylcholine (DPPC) Langmuir monolayers by mounting a Langmuir-trough on a wide-field fluorescence microscope with single molecule sensitivity. This made it possible to directly visualize the activity and diffusion behavior of single PLA(2) molecules in a heterogeneous lipid environment during active hydrolysi...

The immobilization of the enzyme tyrosinase (Tyr) in lipid matrices can be explored to produce biosensors for detecting polyphenols, which is relevant food industry. Herein, we shall demonstrate importance composition immobilize Langmuir-Blodgett (LB) films. Tyr could incorporated into Langmuir monolayers arachidic acid (AA), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoy...

The uptake of different surfactant lipids-dipalmitoylphosphatidylcholine (DPPC), phosphatidylglycerol (PG), or phosphatidylinositol (PI)-and liposomes with a surfactant-like composition by alveolar type II cells (alveolar type II cells) and macrophages (alveolar macrophages) was studied in vitro. Fluorescent-labeled liposomes containing either 86% of the studied lipid, i.e., DPPC, PG, PI, and 6...

The role of surfactant protein-A (SP-A) in pulmonary uptake and metabolism of [(3)H]dipalmitoylphosphatidylcholine ([(3)H]DPPC) was studied in SP-A gene-targeted mice (SP-A -/-). Unilamellar liposomes were instilled into the trachea of anesthetized mice. Uptake was measured as dpm in lungs plus liver and kidney for in vivo experiments and in lungs and perfusate for isolated lung experiments. [(...