Respirable Particulate Surface Interactions with the Lecithin Component ofPulmonary Surfactant

摘要

The prophylactic effect of dipalmitoyl-lecithin (DPL) adsorption to respirablequartz (14808607) and kaolin (1332587) dusts was examined so far as potential toxicity for lung cells was concerned. Fourier transform infrared spectroscopy (FTIR) and photoacoustic spectroscopy of lecithin on quartz and of lecithin on kaolin were carried out. The surface toxicity both of quartz and kaolin dusts was eliminated in short term cytotoxicity assays. Quartz was readily retoxified by phospholipase-A2 in a cell free in-vitro system and was relatively free of retained phospholipids. Kaolin was not readily retoxified at comparable enzyme levels and retained both DPL and phospholipid degradation products. The pH dependence suggested that both quartz and kaolin have acidic surface groups that are involved in hemolysis, and may also be associated with the positively charged trimethylamine group of DPL. FTIR spectra suggested that kaolin probably interacts with the phsophate group of DPL, and both quartz and kaolin probably interact with the trimethyl amine group. There may be a surface chemistry effect in the differing rates of hydrolysis by phospholipase-A2.