Researchers from Cal Berkeley and Solidus Biosciences Inc. have developed biochips that might eventually eliminate the need for animal testing in the chemical and cosmetics industries. The MetaChip and the DataChip, will show potential toxicity of chemicals and drug candidates on organs in the human body.
The biochip, announced this week in the online edition of the Proceedings of the National Academy of Sciences, is a suspension of more than a thousand human cell cultures in a three-dimensional gel on a standard microscope slide. Each cell culture is capable of assessing the toxicity of a different chemical. According to researchers from the University of California, Berkeley, Rensselaer Polytechnic Institute and Solidus Biosciences, Inc. of Troy, N.Y., cultures of skin cells in this so-called DataChip could be used to rapidly screen new chemicals for skin toxicity or irritability.
By adding other types of cells, such as lung or heart cells, and combining the DataChip with another biochip - the MetaChip - that the researchers created several years ago, cosmetics or chemical companies could also test whether chemicals are toxic to other organs, not just skin.
"The DataChip expands the capabilities of the MetaChip and enables it to test for toxic effects of chemicals and their metabolites throughout the body," said co-lead author Douglas S. Clark, UC Berkeley professor of chemical engineering and co-founder of Solidus Biosciences, the company that is working to commercialize the chips. "It is one step closer to a replacement for animals in evaluating product safety, as well as to a personalized system that can predict the toxicity of drugs in individual patients."
The MetaChip that was reported two years ago contains liver enzymes immobilized on a microscope slide. Liver enzymes can sometimes alter seemingly safe chemicals and make them toxic. The MetaChip mimicks this process, quickly metabolizing a chemical to produce compounds the liver itself would produce. The DataChip provides an equally fast way to determine the effect of these metabolites on cells.
For drug companies, the combination of the MetaChip and the DataChip offers a rapid way to predict whether a drug candidate or its metabolite is toxic. The chips will also enable chemical companies to comply with new legislation stipulating that chemicals undergo toxicity analysis.
"We looked at the issues facing companies and realized that we needed to develop something that was low-cost, high-throughput, easily automatable and did not involve animals" said co-lead author and Solidus Biosciences co-founder Jonathan S. Dordick, the Howard P. Isermann '42 Professor of Chemical and Biological Engineering at Rensselaer. "We developed the MetaChip and DataChip to deal with the two most important issues that need to be assessed when examining the toxicity of a compound - the effect on different cells in our body and how toxicity is altered when the compound is metabolized in our bodies."
The collaborative team sees the combined chips as an efficient, more accurate way to test drug compounds for toxicity earlier in the discovery process, before a lot of money has been invested in a drug candidate. However, according to Clark, pharmaceutical companies are only one potential user, and not necessarily the first.
Monday, 12 May 2008
