Comparative effects of fibrous and nonfibrous minerals on cells and liposomes

Our plain-English summary of Comparative effects of fibrous and nonfibrous minerals on cells and liposomes, by C.D. Woodworth, B.T. Mossman, J.E. Craighead (Environmental Research, 1982).

The study

• Authors: C.D. Woodworth, B.T. Mossman, J.E. Craighead
• Journal: Environmental Research
• Published: 1982;27(1):190-205
• Cited by: 27 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The comparative effects of chrysotile asbestos, silica, talc, kaolinite, and montmorillonite on cellular and artificial membranes were examined using three test systems-monolayer cultures of tracheal epithelial cells, suspensions of sheep erythrocytes (RBC), and preparations of phospholipid-cholesterol vesicles. The four minerals caused perturbations in each system, although to varying degrees. Membrane alterations induced by chrysotile asbestos and the clay mineral montmorillonite were more striking than those caused by other dusts. The results obtained with the three test systems were consistent. Electron microscopic observations indicated that the particles were phagocytized by cultured epithelial cells of hamster tracheal origin and developed intimate associations with the RBC plasma membrane. These interactions are discussed with regard to possible mechanisms of cellular injury and their relevance to pulmonary disease.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This was a laboratory study, not a study of people. The authors compared how five minerals affected cell membranes: Canadian chrysotile asbestos, silica (alpha quartz), talc, kaolinite and montmorillonite (the last two are clay minerals). They used three test systems: a cloned line of tracheal (windpipe) lining cells from the Syrian hamster, red blood cells from sheep, and artificial fat-based membrane bubbles called liposomes. Membrane changes caused by chrysotile and montmorillonite were more striking than those caused by the other dusts, and the three test systems gave consistent results. In the hamster cells, each mineral was toxic after 24 hours, and the cells engulfed the particles. Montmorillonite and chrysotile damaged red blood cells at lower concentrations than the other minerals, and chrysotile visibly distorted red cell membranes. The authors noted that particle size, shape and number per unit weight were not standardized. They suggested that large particles in the talc and silica samples might explain why those two were less active. They also stated that mechanisms other than direct membrane damage may be important.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: laboratory (in vitro) experiment comparing minerals in three test systems, with scanning and transmission electron microscopy
• Who was studied: no human subjects; a cloned tracheal epithelial cell line from the Syrian hamster (strain 87.20), fresh sheep red blood cells from a single donor, and artificial phospholipid-cholesterol vesicles (liposomes)
• Exposure: Canadian chrysotile asbestos (International Union Against Cancer reference sample), silica (alpha quartz), talc, kaolinite and montmorillonite, added in suspension at a range of concentrations
• Main results:
  • In the hamster tracheal epithelial cells, each mineral was cytotoxic after 24 hours; chrysotile and montmorillonite induced the most striking changes
  • The hamster tracheal epithelial cells engulfed (phagocytized) the particles
  • In sheep red blood cells, montmorillonite and chrysotile caused hemolysis (bursting of red cells) at lower concentrations than the other minerals
  • In the time-course test on red blood cells (each dust at a dose giving 50% hemolysis after 1 hour), hemolysis was rapid, with about 50% of red cells hemolyzed within 10 minutes
  • Under the electron microscope, distortion of the red blood cell membrane was pronounced after exposure to chrysotile and less prominent with the other minerals
  • In artificial liposomes, chrysotile and montmorillonite caused the greatest increase in permeability
  • The authors reported that minerals interacted with artificial lipid membranes in the absence of protein molecules
• The authors' conclusion: The authors concluded that membrane alterations caused by chrysotile asbestos and the clay mineral montmorillonite were more striking than those caused by the other dusts, and that the results of the three test systems were consistent
• Limitations the authors state:
  • Particle size and shape, and the total number of particles per unit weight, were not standardized
  • The talc and silica samples contained a proportion of very large particles, which might explain why those two minerals were relatively inactive
  • The relevance to lung fibrosis is speculative; mechanisms other than direct membrane damage may be important
  • When inhaled, particles probably become coated by substances in the respiratory tract, which probably makes them less cytotoxic than in these tests

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile, Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Chrysotile, Talc.

Related studies

• In vitro assays to predict the pathogenicity of mineral fibers — B.T. Mossman, A.M. Sesko (1990)
• Cytotoxic action of mineral dusts on CHV 79 cells in vitro: factors affecting toxicity — S.O. Lock, M. Chamberlain (1983)
• Studies using lectins to determine mineral interactions with cellular membranes — B.T. Mossman, L. Jean, et al. (1983)
• Effects of nonfibrous minerals in the V79-4 cytotoxicity test — G.H. Pigott, P.J. Pinto (1983)
• Effect of mineral dusts on metabolic cooperation between Chinese hamster V79 cells in vitro — M. Chamberlain (1983)
• The chemiluminescent response of human phagocytic cells to mineral dusts — I.P. Gormley, M.J. Kowolik, et al. (1985)

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