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.