Studies on the Nature of Silicosis: A Suggested Mechanism of Fibrogenesis

Abstract

One theory which seeks to explain the production of fibrous tissue in silicosis postulates the interaction of collagen precursors with polysilicic acid. This stage has been questioned because it is doubtful whether polymerized silicic acid is normally formed when quartz dissolves in aqueous media. A mechanism by which silicic acid may be polymerized in vivo has been demonstrated by studying the properties of polyamide monolayers, which behave like collagen monolayers when spread on silicic acid substrates. The silicic acid which is adsorbed beneath the monolayer polymerizes when the polyamide films are subjected to pressure.In fibrogenesis, the polysaccharides which are produced in large amounts may serve to prevent the premature agglomeration of the collagen units. Later, when the concentration of the polysaccharide is largely reduced, the polysaccharide may assist in aligning and cementing the units together to form fibres. The physiological process is probably reversible but, if silicic acid takes the role of the polysaccharide in this second stage, the building up of fibres is likely to be an irreversible process.

Fluorescent nanonetworks: A novel bioalley for collagen scaffolds and Tissue Engineering

“…During the 50's, the ability of polysaccharides to stabilize collagen was reported. The involvement of hydroxyl groups in the polysaccharide attached to collagen surface in the process of fibril stabilization was put forth 29 . However, in later years, the involvement of acidic polysaccharides was discounted 30 .…”

Minerals, Fibrosis, and the Lung

“…However, this concept fell into disrepute when disparities emerged between solubility and fibrogenicity, in respect ofamorphous and different crystalline modifications ofsilica and ofdifferently sized particles (5,9), as well as when silica particles of various forms were etched with hydrofluoric acid or sodium hydroxide (13). An extended solubility theory envisaged that precursors of collagen adsorbed silicic acid, which induced them to polymerize into mature forms (14), but this idea too did not overcome the objections. Diffusion chamber experiments also offered no support to simple solution as the means by which silica led to fibrosis.…”