ABSTRACT
A series of 12 organosilicon compounds representing potential intermediates in the synthesis and degradation of polydimethylsiloxanes were evaluated for genotoxic potential with a battery of in vitro assays. Microbial assays included the Ames bacterial reverse mutation in Salmonella, mitotic gene conversion in Saccharomyces cerevisiae D4 and DNA repair in E. Coli pol A +/-. These assays were conducted with and without a metabolic activation system containing Aroclor 1254-induced rat-liver homogenate. Forward gene mutation, sister-chromatid exchange, DNA alkaline elution and chromosome aberration potential were evaluated in mouse lymphoma L5178Y tissue culture cells. The tissue culture assays were performed with and without metabolic activation mixture utilizing uninduced mouse-liver S-9. The use of this enzyme preparation was felt to more closely mimic the actual in vivo situation and to be more compatible with mouse cells employed in the assay. No evidence of gene mutation was observed. However, six of the 12 compounds evaluated demonstrated potential in vitro clastogenic (chromosome damaging) activity.
Subject(s)
Mutagens , Silicon/toxicity , Animals , Chromosome Aberrations , Dimethylpolysiloxanes/toxicity , Escherichia coli/genetics , Leukemia L5178/genetics , Mice , Mutagenicity Tests/methods , Saccharomyces/genetics , Salmonella/genetics , Sister Chromatid Exchange/drug effects , Tumor Cells, CulturedABSTRACT
Six organosilicon compounds which had been found to have clastogenic activity in an in vitro battery of genotoxicity assays were evaluated in rat bone marrow cytogenetic assays for assessing clastogenicity in an in vivo system. None of the six compounds produced significant increases in chromosome aberrations in the rodent assay. However, trimethylsilanol produced a single value at the high-dose level/48-hr sampling interval that was significantly elevated when compared to the low concurrent control value. Both an independent repeat of the bone marrow cytogenetic assay and performance of the rat dominant lethal test failed to substantiate the presence of any significant clastogenic activity. Organosilicon compounds involved in the synthesis and degradation of polydimethylsiloxanes were not genotoxic in the in vivo clastogenicity tests employed in these studies.
Subject(s)
Mutagens , Silicon/toxicity , Animals , Bone Marrow/drug effects , Bone Marrow/ultrastructure , Chromosome Aberrations , Dimethylpolysiloxanes/toxicity , Genes, Dominant/drug effects , Genes, Lethal/drug effects , Male , Mutagenicity Tests/methods , Rats , Rats, Inbred Strains , Trimethylsilyl Compounds/toxicityABSTRACT
An antimicrobial-surface kinetic test which maximizes probability of cell-to-surface contact has been developed. The measurement of rate of kill by a nonleaching antimicrobial surface is based on the number of surviving bacterial cells at specific times of exposure to various amounts of total treated surface area of test substrate. This method gives information for direct comparison of rate of kill for a variety of antimicrobial surfaces in terms of rate of kill per square centimeter of surface area. Data obtained by this method can also give valuable dose response application information as an indication of the exponential efficiency of concentration in terms of treated surface area.
Subject(s)
Bacteriological Techniques , Disinfectants , Escherichia coli/drug effects , Silicon/pharmacology , Trimethylsilyl Compounds/pharmacology , Dose-Response Relationship, Drug , Quaternary Ammonium Compounds/pharmacology , Surface PropertiesABSTRACT
The hydrolysis product of a quaternary amine-containing organosilicon salt, 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride, was found to exhibit algicidal activity while chemically bonded to a variety of substrates. Six representative species of Chlorophyta, Cyanophyta, and Chrysophyta were used to evaluate the algicidal activity. Substrate-bonded (14)C-labeled organosilicon quaternary ammonium salt when attached to nonwoven fibers was durable to repeated washings, and algicidal activity could not be attributed to slow release of the chemical.
Subject(s)
Ammonium Chloride/pharmacology , Eukaryota/drug effects , Water Microbiology , Benzalkonium Compounds/pharmacology , Carbon Isotopes , Chlorophyta/drug effects , Chlorophyta/growth & development , Culture Media , Cyanobacteria/drug effects , Cyanobacteria/growth & development , Eukaryota/growth & development , Gossypium , PolymersABSTRACT
The hydrolysis product of 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride exhibited antimicrobial activity against a broad range of microorganisms while chemically bonded to a variety of surfaces. The chemical was not removed from surfaces by repeated washing with water, and its antimicrobial activity could not be attributed to a slow release of the chemical, but rather to the surface-bonded chemical.
