THE ROLE OF NATURE AND STRUCTURE OF SURFACE SITES IN THE BIOLOGICAL RESPONSE TO SILICA PARTICLES

摘要

The inhalation of crystalline silica dusts causes lung inflammation and the development of silicosis and lung cancer. Inhalation of amorphous silica dusts seems to elicit no adverse biological response. The large variability in toxicity elicited by quartz dusts having different origins may be assigned to differences in the surface structures of the particles. When a silica particle is in contact with body fluids, adsorption and surface reactions with endogenous molecules (e.g. proteins and pulmonary surfactant) take place. These reactions can modify the surface properties of the silica particles and consequently modulate the pathogenic responses elicited. In this work we study the adsorption of bovine serum albumin (BSA) on different amorphous and crystalline silica dusts, the occurrence of conformational changes of the protein during the adsorption process, and the effect of some surface properties (hydrophilicity, presence at the surface of metal impurities and defects) on the amount of proteins adsorbed.