Polymers reverse inactivation of surfactant induced by plasma

Abstract

Objective Objective A variety of substances including plasma have been found to affect adversely the surface tension-lowering activity of pulmonary surfactant,and this effect may be important in the pathogenesis of a number of human diseases such as acute lung injury(ALI) and acute respiratory distress syndrome(ARDS).We were aimed at exploring whether inactivation of surfactant induced by plasma could be prevented or reduced by polymers.Methods We measured the maximum(γmax)and minimum sueface tension(γmin) of dextran, polyethylene glycol (PEG), hyaluronan(HA),pulmonary surfactant(Curosur), plasma and their mixtures by captive bubble surfactometer,respectively.Values of stability index(S.I.) were also calculated.Results The γmin of different polymers,plasma and their mixtures were more than 10 mN/m and S. I. of which were less than 0.8.The γmin and S. I. of Curosurf(1.25mg/ ml) were (1.54±0.03)mN/m and 1.71±0.01 ,respectively.The min and S.I.of Curosurf mixed with 1%,2% or 3% plasma were(19.0±0.46)mN/m, (22.9±0.42)mN/m and(22.6±1.22)mN/m and 0.38±0.05,0.34±0.02 and0.39±0.15, respectively. When mixed with 5% PEG, 5% dextran and 0.25% HA, the γmin significantly decreased to[(1.59±0.22)mN/m, (1.43±0.24)mN/m, (17.2±0.72)mN/m; (0.88±0.06) mN/m, (1.18±0.06) mN/m,(1.46±0.22)mN/m and (1.22±0.10)mN/m,(1.33 ～ O.O7 )mN/m, ( l.42 ～ O. 18 )mNIm,mspecfively, ( P <O.O6 ) ,and the S.I.significantly increasedto to 1.72～0.04,1.73～0.04,0.43～0.04;1.82～0.01,1.82～0.01,1.79～0.03 and 1.79 ～ 0.02,1.79 ～ 0.01,1.79 ～ 0.04, reapeetively, ( P < 0.05 ). Different concentrations of polymers signifieandy enhanced the ability of Curosurf in reducing the Train and elevating S. 1. in the presence of plasma.Polymers are capable of reversing inactivation of surfactant induced by plasma in vitro. The data suggests that dextran and HA be more effective to lower the ～nin than PEG when mixed with Curosurf. Key words: Polymera; Putmonary Surfactants; PLasma; Minimum Surface Tension; Stability Index