Surfactant phospholipids

Fig. 1.4. Examples of surfactants, phospholipids and polymers with covalently bound probes. 1 2-(9-anthroyloxy)stearic acid. 2 6-(9-anthroyloxy)stearic acid.

The positively charged amino acids promote the interaction between the peptide and the negatively charged head groups of the phosphatidylgly-cerol (123-125). The purpose of this particular property has been proposed to facilitate the transition of surfactant phospholipid membranes from the lamellar body to the alveolar spaces (123). 

According to Helenius and Simons (30) solubilization of the membrane is preceded by saturation of the bilayer with surfactant. Certainly critical surfactant/phospholipid ratios must be attained before membrane disruption occurs. 

J Bruch, E Gono, W Malkusch. B Rehn. Improved method for quantitative analysis of lung surfactant phospholipids in bronchoalveolar lavage fluids by high performance hquid chromatography. Clin Chim Acta 231 193-204, 1994. 

H Buenger, U Pison. Quantitative analysis of pulmonary surfactant phospholipids by high performance liquid chromatography and light scattering detection. J Chromatogr B 672 25-31, 1995. 

This section will focus primarily on the development of nonviral vectors that are based on surfactants, phospholipids, and natural or synthetic polymers for their application to the delivery of macromolecules, mainly of genetic materials such as DNA or RNA. Development of safe and efficient vectors will expedite the success of human gene therapy, which has captured the attention recently of the public and the biomedical research community. Even though more and more new delivery vectors are being introduced into the scientific milieu with enhanced efficiency, it should be emphasized that safety always goes first, especially after the tragedy of J. Gelsinger in 1999. 

Calfactant is purified surfactant phospholipids extracted from calf lungs and purified by gel permeation chromatography. Calfactant include phospholipids, neutral lipides, and hydrophobic surfactant - three biophysically active proteins SP-A, SP-B, and SP-C. It contained no preservatives. 

The h(Cei) dependences (at pG = const and t = const) are studied also for other surfactants, phospholipids and polymers, and they have proved to be very informative with respect to not only the CBF/NBF transition and Cei,cr values, but also surface forces acting in black foam films (see Sections 3.3. and 3.4). 

Positioned at the interface between the air and tear film, the lipid layer is produced by the meibomian glands with contributions from the glands of Zeis and Moll. Most of this layer consists of low-polarity lipids, such as wax and cholesterol esters, with traces of triglycerides. A thin polar portion, adjacent to the tear-aqueous layer, may contain surfactant phospholipids needed to spread lipid film over aqueous layers. The main purpose of the lipid layer appears to be to reduce evaporation of the tear film. 

Fluorescence polarization is a dimensionless ratio with values from 0.000 to 0.500 for dilute solutions containing fluorescing compounds (see Chapter 3). Polarization (P) measures the rotational diffusion of the fluorophore relative to its fluorescent half-life. If the half-life is short compared with the rate of rotational diffusion, P will be high. In contrast, if molecular rotation is faster than the excited state decay, then P wfll be low. Shinitzky proposed that for amni-otic fluid, lower polarization values reflected a decrease in the microviscosity of surfactant phospholipids. The fluidity of these phospholipids paralleled the change in lipid composition with maturation of the fetal lungs. This mechanism is incorrect for the NBD-PC method. NBD-PC binds to albumin and to surfactant thus the resulting polarization is a function of the surfactant/albumin ratio. ... 

Torday J, Rehan V (2011) Neutral lipid trafficking regulates alveolar type II cell surfactant phospholipid and surfactant protein expression. Exp Liang Res 37(6) 376-386... 

Rice WR, Singleton FM (1989) Reactive blue 2 selectively inhibits P2y-purinoceptor-stimulated surfactant phospholipid secretion from rat isolated alveolar type II cells. Br J Pharmacol 97(1) 158-162... 

Lipschik GY, Treml JE, Moore SD, Beers MF (1998) Pneumocystis carinii glycoprotein A inhibits surfactant phospholipid secretion by rat alveolar type II cells. J Infect Dis 177(1) 182-187... 

Ansceschi, M. (1989). The alveolar type 11 cells as a model for investigating the metahohsm of surfactant phospholipids. Eur Respir J Suppl 3, lOs-12. 

Jugg B, Jenner J, Rice P. The effect of perfluoroisobutene and phosgene on rat lavage fluid surfactant phospholipids. Hum Exp Toxicol, 1999 18 659-668. 

Fatty acids Saponification Micelles Surfactant Phospholipids Waxes Steroids Cholesterol... 

With the increasing demand for skin care and repair products, the personal care market is evolving toward even milder, essentially nonirritating cleansing formulations. To design such skin-compatible compounds, it is only natural to attempt to imitate the functional characteristics of the biochemical surfactants, phospholipids. The phosphocholine moiety is the most common hydrophilic group, usually coupled to a diglyceride hydrophobe unit as in lecithin, a phospholipid commercially extracted from egg and soybean products. 

K., and Hanaoka, K. (1996). Sensitive method for the determination of pulmonary surfactant phospholipid/sphingomyelin ratio in human amniotic fluids for the diagnosis of respiratory distress syndrome by thin-layer chromatography-immunostain-ing. Anal. Biochem. 238 29-33. 

Emulsions are thermodynamically unstable structures given a degree of kinetic stability by an adsorbed interfacial layer of amphiphilic emulsifiers. The emulsifiers serve to lower the interfacial tension and provide some inter-droplet repulsive forces to stabilize the dispersions (e.g., steric and electrostatic). The interfacial layer is typically between about 1 and lOnm thick for food grade emulsifiers, such as surfactants, phospholipids, proteins, or polysaccharides, and the interfacial concentration is in the order of a few mg per square meter of surface (McClements, 2005 McClements and Decker, 2000). 

The reason(s) for the difference in equilibrium surface tensions of airway and alveolus are unknown, but they may reflect differences in the composition, concentration, or both, of the surfactant of the two compartments. As the rate of adsorption of lipids to the film interface depends on both the composition and concentration of the surfactant phospholipids and the associated surfactant proteins (23,65), the low SP-A and absent SP-B and SP-C in the pig tracheal fluid in the foregoing experiments (44) may account for the higher static adsorptions observed in the tracheal fluids from this species. 

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