Comparison of in vitro Surface Physical Properties of Four Artificial Exogenous Pulmonary Surfactant Preparations

PURPOSE: We conducted this study to compare the surface physical properties of four commercial preparations of artificial exogenous pulmonary surfactants in vitro which have been used in both the prevention and treatment of respiratory distress syndrome in newborn infants. METHODS: We tested four surfactants : a) Surfacten (Tokyo Tanabe, Japan) and Newfactan (Yuhan, Korea) : reconstituted bovine lung extract, b) Curosurf (Cheisi, Italy) : porcine lung mince; chloroform-methanol extract; liquid-gel chromatography, and c) Exosurf (Wellcome, USA), synthetic surfactant composed of colfosceril, palmitate, hexadecanol, and tyloxapol. We measured the surface adsorption rate, spreading rate, and surface tension(ST)-area diagram by using modified Wilhelmy balance and minimum(min-ST) and maximum ST(max-ST) by Pulsating Bubble Surfactometer. RESULTS: The adsorption rate of Surfacten is less than 30mN/m and those of Newfactan, Curosurf, and Exosurf are more than 30mN/m. The spreading rate of Surfaten and Newfactan are less than 30mN/m, and those of Curosurf and Exosurf are more than 30mN/m. The min-ST of Surfacten and Newfacten are less than 10mN/m, and those of Curosurf and Exosurf are more than 10mN/m. According to high performance of surface physical activities, which are compared with in vitro criteria of effective artificial surfactant, they are as follows; Surfacten>Newfactan>Curosurf>Exosurf. CONCLUSION: There are some differences between the surface physical properties of the four surfactant preparations. The natural surfactants appear to be superior to synthetic surfactant in vitro. Among the natural surfactants, Surfacten showed the best surface physical activities of spreading, adsorption and ST-lowering properties.

Effects of Two Different Surfactants on RBC Membrane and Type II Alveolar Epithelial Cell in Vitro

PURPOSE: Respiratory distress syndrome(RDS) is a major cause of death in premature babies. For the treatment of RDS, various artificial pulmonary surfactants have been used. The incidence of pulmonary hemorrhage is increased in association with surfactant therapy in extremely low birth weight infants. But the pathogenesis of this increased incidence is not clear. So we conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to Surfacten(R) or Exosurf(R) or additive component of Exosurf(R) may lead to increased membrane permeability. METHODS: Washed packed RBC(30microliter) with various concentrations of Surfacten(R), Exosurf(R), hexadecanol and tyroxapol(concentration similar to their content in each Exosurf(R)), were incubated for 2, 24 and 48 hour at 37degrees C. Hemolysis was measured by spectrophotometry. Type II alveolar epithelial cell(HTB-181)(106cell/mL) with 2, 4, 6 and 8mg of Surfacten(R) or Exosurf(R) were incubated for 24 hour at 37degrees C. Lactate dehydrogenase(LDH) release was measured as an indicator of cytotoxicity. RESULTS: RBC hemolysis was increased in a time and dose-dependent manner with both artificial surfactants and additive components of Exosurf(R). This trend, especially, was typically seen in the sample which was incubated for 24 hours, where more hemolysis was seen with Exosurf(R) and tyroxapol than Surfacten(R) and hexadecanol with the above concentration of 2.5mg/2mL(P<0.05). LDH released from type II alveolar epithelial cell with Exosurf(R) was greater than with Surfacten(R), especially at the concentration of 6mg/106cell(P<0.05). CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity on RBC membrane and aveolar epithelial cell, and this property was more prominent with Exosurf(R) and the additive components of Exosurf(R), especially with tyroxapol.

Effects of Two Different Surfactants on RBC Membrane and Type II Alveolar Epithelial Cell in Vitro

PURPOSE: Respiratory distress syndrome(RDS) is a major cause of death in premature babies. For the treatment of RDS, various artificial pulmonary surfactants have been used. The incidence of pulmonary hemorrhage is increased in association with surfactant therapy in extremely low birth weight infants. But the pathogenesis of this increased incidence is not clear. So we conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to Surfacten(R) or Exosurf(R) or additive component of Exosurf(R) may lead to increased membrane permeability. METHODS: Washed packed RBC(30microliter) with various concentrations of Surfacten(R), Exosurf(R), hexadecanol and tyroxapol(concentration similar to their content in each Exosurf(R)), were incubated for 2, 24 and 48 hour at 37degrees C. Hemolysis was measured by spectrophotometry. Type II alveolar epithelial cell(HTB-181)(106cell/mL) with 2, 4, 6 and 8mg of Surfacten(R) or Exosurf(R) were incubated for 24 hour at 37degrees C. Lactate dehydrogenase(LDH) release was measured as an indicator of cytotoxicity. RESULTS: RBC hemolysis was increased in a time and dose-dependent manner with both artificial surfactants and additive components of Exosurf(R). This trend, especially, was typically seen in the sample which was incubated for 24 hours, where more hemolysis was seen with Exosurf(R) and tyroxapol than Surfacten(R) and hexadecanol with the above concentration of 2.5mg/2mL(P<0.05). LDH released from type II alveolar epithelial cell with Exosurf(R) was greater than with Surfacten(R), especially at the concentration of 6mg/106cell(P<0.05). CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity on RBC membrane and aveolar epithelial cell, and this property was more prominent with Exosurf(R) and the additive components of Exosurf(R), especially with tyroxapol.

A Study of Relation between Stable Microbubble Rating and Surfactant Derivatives (Surfacten : Phospholipid :, Exosurf :Dipalmitoyl-Phosphatidyl Choline) Concentration in Vitro

PURPOSE: With the recent advent of surfactant replacement therapy, there is an increasing need for a rapid and reliable test to predict respiratory distress syndrome (RDS) immediately before or at birth. There are many investigations and methods for the detection of RDS in prenatal or postnatal period. The stable microbubble rating test (SMR-test) developed by pattle et al. is rapid and simple test performed on amniotic fluid and gastric aspirates which reflects the adequacy of pulmonary surfactant with higher diagnostic accuracy. To determine the relation of the SMR and surfactant derivatives [Surfacten : phospholipid (PL), Exosurf : dipalmitoyl-phosphatidyl choline (DPPC) concentration in vitro, author performed SMR test according to 15 groups of surfactant derivatives concentration by using modified Pattle's method. METHODS: Surfacten & Exosurf were diluted each concentration (0, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100microgram/ml) by dilutional fluid. We enveloped test tube by paraffin paper for protection of evaporation. When we performed SMR test, we shaked test tube vigorously by Vlotex shaker. We performed SMR test according to 15 groups of Surfactant concentration by using modified Pattle's method. RESULTS: 1) The number of SMR according to 15 groups of surfactant derivatives concentration were 2, 1/mm2 in 4.2microgram/ml of PL and 3.1microgram/ml of DPPC, 279, 1104/mm2 in 83.3microgram/ml of PL and 61.8microgram/ml DPPC. 2) The regression curve of SMR and surfactant derivatives concentration showed statistically significant relation (p<0.005). CONCLUSION: The SMR test was a good method in estimation of surfactant concentration in vitro and also in diagnosis of RDS recognized as a surfactant deficiency.