Development of low cost pulmonary surfactants composed of a mixture of lipids or lipids–peptides using higher aliphatic alcohol or soy lecithin

The artificial pulmonary surfactant composition in the present study is characterized by a lipid mixture system composed of higher aliphatic alcohol, egg yolk phosphatidylcholine (egg PC), soy lecithin and higher aliphatic acid as the major components or a peptide–lipid mixture system composed of a combination of the lipid mixture system to which a peptide is added. Three peptides with amphiphilic surface-staying, membrane spanning, and both properties were designed and synthesized. The evaluation of pulmonary surfactant assay was performed by a hysteresis curve drawn upon the measurement for the surface tension–area curve with the Wilhelmy surface tensometer in vitro and the recovery of lung compliance for the pulmonary surfactant-deficient rat models in vivo. Lipid-mixture systems composed of octadecanol or soy lecithins containing no peptide were favorable hysteresis curves as compared with commercially available Surfacten®, but were not prominent. The peptide–lipid mixture systems composed of a combination of the lipid mixture of alkyl alcohol or soy lecithin to which peptides designed were added were desirable hysteresis curves similar to Surfacten® and amphiphilic Hel 13-5 peptide–lipids mixture systems were much more effective than the lipid mixture system. Particularly, the recovery of lung compliance treated with hydrogenated soy lecithin–fractionated soy lecithin PC70–palmitic acid–peptide Hel 13-5 (40:40:17.5:2.5, w/w) was comparable to that with Surfacten®. Because the artificial pulmonary surfactant compositions of this study can be prepared at lower costs, they are useful for the treatment of respiratory distress syndrome and acute respiratory distress syndrome as well as for inflammatory pulmonary diseases, dyspnea caused by asthma, etc.