title: Development of a Synthetic Surfactant Using a Surfactant Protein-C Peptide Analog: In Vitro Studies of Surface Physical Properties.
abstract: OBJECTIVE
  Pulmonary surfactant (PS) replacement has been the gold standard therapy for neonatal respiratory distress syndrome; however, almost all commercial PSs contain animal proteins. We prepared a synthetic PS by using a human surfactant protein (SP) analog and evaluated its in vitro properties.
  
  
  METHODS
  A peptide sequence (CPVHLKRLLLLLLLLLLLLLLLL) of human SP-C was chosen to develop the peptide analog (SPa-C). The new synthetic SP-C PS (sSP-C PS) was synthesized from SPa-C, dipalmitoyl phosphatidylcholine, phosphatidyl glycerol, and palmitic acid. Physical properties of the sSP-C PS were evaluated by measuring the maximum and minimum surface tensions (STs), surfactant spreading, and adsorption rate. In addition, we recorded an ST-area diagram. The data obtained on sSP-C PS were subsequently compared with those of purified natural bovine surfactant (PNBS), and the commercial product, Surfacten®.
  
  
  RESULTS
  The sSP-C PS and Surfacten® were found to have maximum ST values of 32-33 mN/m, whereas that of PNBS was much lower at 19 mN/m. The minimum ST values of all three products were less than 10 mN/m. The values that were measured for the equilibrium ST of rapidly spreading sSP-C PS, Surfacten®, and PNBS were 27, 27, and 24 mN/m, respectively. The surface adsorptions were found to be the same for all three PSs (20 mN/m). ST-area diagrams of sSP-C PS and Surfacten® revealed similar properties.
  
  
  CONCLUSIONS
  In an in vitro experiment, the physical properties exhibited by sSP-C PS were similar to those of Surfacten®. Further study is required to evaluate the in vivo efficacy.
authors.affiliation: Department of Pediatrics, Kyung Hee University School of Medicine, Seoul, Korea. baecw@khnmc.or.kr.
authors.forename: Chong Woo
authors.initials: CW
authors.lastname: Bae
authors.affiliation: Department of Pediatrics, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Chung
authors.affiliation: Department of Pediatrics, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Yong Sung
authors.initials: YS
authors.lastname: Choi
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives; D000327:Adsorption; D000595:Amino Acid Sequence / Q000235:genetics*; D000818:Animals; D002096:C-Peptide / Q000737:chemistry*; D002417:Cattle; D006801:Humans; D007231:Infant, Newborn; D037721:Pulmonary Surfactant-Associated Protein C / Q000138:chemical synthesis* / Q000494:pharmacology; D011663:Pulmonary Surfactants / Q000138:chemical synthesis* / Q000494:pharmacology; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy*; D013499:Surface Properties; D013500:Surface Tension; D013501:Surface-Active Agents
chemical_list: D002096:C-Peptide; D037721:Pulmonary Surfactant-Associated Protein C; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; D015060:1,2-Dipalmitoylphosphatidylcholine; C081581:colfosceril palmitate
keywords: Pulmonary surfactant; respiratory distress syndrome; surface tension; surfactant protein-C; synthetic peptide syntheses