Binding of silicic acid by proteins and its relation to toxicity of silicate dusts.

A possible mechanism of biological effects of silicate dusts is the interaction between silicic acid and tissue constituents, and this has been studied in vitro. On incubating silicic acid with lung homogenate, appreciable amounts of silicon were recovered in the trichloroacetic acid precipitate in both organic solvent extract and residual protein. Polyvinyl pyrrolidone inhibited this interaction as well as reducing the dissolution of silicic acid from asbestos dust. The capacity of serum albumin to bind silicic acid was also observed. Chemical interaction between macromolecules and silicic acid could be one of the factors responsible for the biological effects of silicon-containing dusts.