Researchers from the National Institute of Agrobiological Societies in Tsukuba, Ibaraki Prefecture have developed a layer of cells suspended on an ultrathin collagen sheet which can be used to measure the toxicity of chemicals.
In experiments, the new substance gave the same results as previously developed toxicity tests in 90 percent of cases. The team’s findings were first published in the British online journal ‘Toxicological Science’ on July 20.
Head researcher Toshiaki Takezawa said: "We developed a novel human corneal epithelium (HCE) model by three-dimensionally culturing HCE-T cells (a HCE-derived cell strain) in a collagen vitrigel membrane chamber." He also says that the product is more cost-efficient than animal testing.
The experiment, known as the Vitrigel-EIT method, involved 30 toxicity experiments in total. The researchers tested the chemicals by leaving them on the sheet for three minutes and seeing how many corneal cells were destroyed.
The team reported high correlation with the Globally Harmonized System of Classification and Labelling of Chemicals, with the results showing 100 percent sensitivity, 75 percent specificity and 90 percent accuracy.
The researchers say that their results show that:“the widespread eye irritancy of chemicals can be predicted without false-negatives by the Vitrigel-EIT method.”
The HCE-T cells cultured are commercially available, while the collagen vitrigel membrane chamber used will be sold in Japan beginning from this September.
Takezawa said that the HCE model used will be viable commerically "when its delivery system is established."
The study was supported by Agri-Health Translational Research Project from the Ministry of Agriculture, Forestry and Fisheries of Japan
Japan currently does not have any formal regulations for animal testing, with the main guidelines being the “three r’s,” Replacement, Reduction and Refinement, which are voluntarily followed by companies.
Naoko Kagiyama, an executive member of the Kawasaki-based Central Institute for Experimental Animals, said:“While the finding needs to be verified before it can be practically applied, this is an achievement expected to be utilized in pharmaceutical development.”