Modification of the in vitro activities of amosite asbestos by surface derivatization

Our plain-English summary of Modification of the in vitro activities of amosite asbestos by surface derivatization, by P.H. Evans, R.C. Brown, A. Poole (Journal of Toxicology and Environmental Health, 1983).

The study

• Authors: P.H. Evans, R.C. Brown, A. Poole
• Journal: Journal of Toxicology and Environmental Health
• Published: 1983;11(4-6):535-43
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The in vitro cytotoxicity of amosite asbestos and its silanized and bovine serum albumin conjugated derivatives were studied in two cell lines. The overall cytotoxicity of amosite towards Chinese hamster lung cells (V79-4) was not affected by derivatization, although the rate of cell-particle interaction was reduced. Protein derivatization virtually abolished the cytolytic action of amosite to the macrophage-like cell line (P388D1), although this derivatized material still induced the release of arachidonate. These results confirm that the in vitro cytotoxic effect of fibrous particulates toward V79-4 cells is mainly dependent on fiber size, while the response of macrophage-like cells is more sensitive to alterations in surface chemistry. The relationship between these results and the pathogenicity of asbestos is discussed.

In plain English

This was a laboratory study using cells grown in culture. The authors tested UICC standard reference amosite asbestos and two chemically altered versions. One was treated with a silane compound. The other had bovine serum albumin chemically bonded to the fiber surface. The aim was to change the fiber surface while keeping fiber size as unchanged as possible. In Chinese hamster lung cells (V79-4) exposed for 6 days, there was no significant difference in toxicity between the three amosite samples. In exposures of up to 1 hour, the altered fibers acted more slowly: the protein-coated amosite was not toxic even after 1 hour, and the silane-treated sample was intermediate. In mouse macrophage-like cells (P388D1), the protein coating virtually abolished amosite's cell-killing effect. The coated fibers still caused release of arachidonic acid. At low doses less was released than with plain amosite, and at the highest doses there was no significant difference. The authors concluded that, given enough time, toxicity to V79-4 cells is determined by fiber size, while macrophage-like cells respond to surface changes in more complex ways.

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: in vitro (cell culture) laboratory experiment
• Who was studied: Two cell lines studied at the M. R. C. Pneumoconiosis Unit, Llandough Hospital, Wales: Chinese hamster lung cells (V79-4) and a murine macrophage-like cell line (P388D1); no humans or animals
• Exposure: UICC standard reference amosite asbestos, plus a silanized derivative (treated with 3-aminopropyl triethoxysilane, APTES) and a derivative with covalently bound bovine serum albumin (BSA). V79-4 cells were exposed continuously for 6 days, or for 15, 30 or 60 minutes at 100 micrograms per ml before dilution. P388D1 cells were exposed for 24 hours at concentrations up to 320 micrograms per ml.
• Main results:
  • Combustion analysis showed that binding of the coating had occurred, but the proportion of fiber surface coated could not be measured.
  • V79-4 cells exposed continuously for 6 days: no significant difference in toxicity between plain, silanized and BSA-derivatized amosite over the concentrations tested.
  • V79-4 cells exposed to plain amosite for short periods: with exposure times of less than 30 minutes, only minimal cytotoxicity was observed.
  • V79-4 cells in short exposures: the derivatized samples interacted more slowly than plain amosite. The BSA-derivatized amosite was not toxic even after 1 hour, and the silanized sample showed intermediate toxicity.
  • P388D1 cells, 24-hour exposure: plain amosite caused significant cell lysis, measured by release of the enzyme LDH. The BSA-derivatized amosite was almost inert; protein coating virtually abolished the lytic effect.
  • P388D1 cells: at low concentrations, arachidonate release was lower with BSA-derivatized amosite than with plain amosite, with the maximum difference at around 80 micrograms per ml.
  • P388D1 cells: at the highest concentrations tested (320 micrograms per ml), arachidonate release did not differ significantly between the two dusts. The authors suggested that this release occurs as a response distinct from cell death.
• The authors' conclusion: The authors concluded that surface chemistry may affect the rate of interaction between fibers and V79-4 cells, but given enough time, cytotoxicity is determined by fiber size. They concluded that the effect on macrophage-like cells is more complex, with different endpoints responding differently to changes in fiber surface.
• Limitations the authors state:
  • The combustion analysis could not give a direct measure of how much of the fiber surface was coated.
  • Fiber size distribution was kept unaltered only as far as possible.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Amosite.

Medical terms in this study, explained in our Lexicon: Amosite, Macrophage.

Related studies

• Surface modification can affect the carcinogenicity of asbestos — R.C. Brown, P. Carthew, et al. (1990)
• The in vitro activities of a highly carcinogenic mineral fibre--potassium octatitanate — A. Poole, R.C. Brown, et al. (1986)
• High aspect ratio materials: role of surface chemistry vs. length in the historical "long and short amosite asbestos fibers" — M. Tomatis, F. Turci, et al. (2010)
• Dissolution Reaction and Surface Modification of UICC Amosite in Mimicked Gamble's Solution: A Step towards Filling the Gap between Asbestos Toxicity and Its Crystal Chemical Features — A. Pacella, P. Ballirano, et al. (2023)
• A study of the effect of chrysotile fiber surface composition on genotoxicity in vitro — M.J. Keane, J.W. Stephens, et al. (1999)
• Asbestos surface provides a niche for oxidative modification — H. Nagai, T. Ishihara, et al. (2011)

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