Naturally derived commercial surfactants differ in composition of surfactant lipids and in surface viscosity

Abstract

Pulmonary surfactant biophysical properties are best described by surface tension and surface viscosity. Besides lecithin, surfactant contains a variety of minor lipids, such as plasmalogens, polyunsaturated fatty acid-containing phospholipids (PUFA-PL), and cholesterol. Plasmalogens and cholesterol improve surface properties of lipid mixtures significantly. High PUFA-PL and plasmalogen content in tracheal aspirate of preterm infants reduces the risk of developing chronic lung disease. Different preparations are available for exogenous surfactant substitution; however, little is known about lipid composition and surface viscosity. Thus lipid composition and surface properties (measured by oscillating drop surfactometer) of three commercial surfactant preparations (Alveofact, Curosurf, Survanta) were compared. Lipid composition exhibited strong differences: Survanta had the highest proportion of disaturated PL and total neutral lipids and the lowest proportion of PUFA-PL. Highest plasmalogen and PUFA-PL concentrations were found in Curosurf (3.8 +/- 0.1 vs. 26 +/- 1 mol%) compared with Alveofact (0.9 +/- 0.3 vs. 11 +/- 1) and Survanta (1.5 +/- 0.2 vs. 6 +/- 1). In Survanta samples, viscosity increased >8 x 10(-6) kg/s at surface tension of 30 mN/m. Curosurf showed only slightly increased surface viscosity below surface tensions of 25 mN/m, and viscosity did not reach 5 x 10(-6) kg/s. By adding defined PL to Survanta, we obtained a Curosurf-like lipid mixture (without plasmalogens) that exhibited biophysical properties like Curosurf. Different lipid compositions could explain some of the differences in surface viscosity. Therefore, PL pattern and minor surfactant lipids are important for biophysical activity and should be considered when designing synthetic surfactant preparations.

Lung Surfactant and Its Use in Lung Diseases

“…Из за опасности иммуно логических реакций удаляют нуклеиновые кислоты, балласт ные белки и большие гидрофильные САБ. Эти процедуры при водят к потере многих минорных компонентов ЛС, отвечающих за способность снижать ПН (плазмалогены и другие минорные липиды) и за защитные и иммуномодифицирующие свойства ЛС [46,128,129]. Чтобы компенсировать эти потери в получае мые смеси липидов добавляют различные компоненты.…”

Surfactants in the Management of Respiratory Distress Syndrome in Extremely Premature Infants

“…14 The composition of surfactants has been studied extensively. Rüdiger et al 15 quantified the lipid components of three natural surfactant preparations: beractant, poractant alfa, and SF-RI1 (Alveofact, Boehringer Ingelheim, Biberach, Germany), and found significant differences in their composition and surface viscosities. The balance between neutral lipids and PL varied widely among the three products (Table 1).…”

“…The mean PL content (expressed in mol%) of SF-RI1, a natural bovine surfactant, was only 23% saturated PL and 66% monoene PL. 15 Beractant, also a bovine derivative, was comprised of 66% saturated PL and 28% monoene PL. Poractant alfa, a porcine lung derivative, consisted of 31% saturated PL, 39% monoene PL, and 26% polyunsaturated PL.…”

“…Unsaturated lipids, particularly polyunsaturated fatty acid (PUFA)-containing PL, have been shown to enhance the fluidity of lipid layers at physiological temperature. 15 Plasmalogen is another lipid component that may significantly improve surfactant properties. 16 Plasmalogens, SP-B and cholesterol 15 regulate the surfactant monolayer stability and viscosity in a synergistic manner.…”

“…15 Plasmalogen is another lipid component that may significantly improve surfactant properties. 16 Plasmalogens, SP-B and cholesterol 15 regulate the surfactant monolayer stability and viscosity in a synergistic manner. 17 The role of plasmalogen has been studied extensively in cardiovascular and neurological disorders.…”