Scientists report that they have taken a step closer to creating a “benchtop human” on which to carry out lab and toxicology tests. Homo minutus, as it is named, is not a real person but rather an interconnected human organ construct.
The latest advance is the successful development and analysis of a constructed human liver that responds to toxic chemical exposure. John Wikswo, Ph.D., professor and director of the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) at Vanderbilt University, presented the results at this week's Society of Toxicology meeting in Phoenix.
Dr. Wikswo said the achievement is the first result from a five-year, $19 million multi-institutional effort led by himself and Rashi Iyer, Ph.D., senior scientist at Los Alamos National Laboratory (LANL). The project is developing four interconnected human organ constructs—liver, heart, lung and kidney—that are based on a miniaturized platform nicknamed ATHENA (Advanced Tissue-Engineered Human Ectypal Network Analyzer).
The project is supported by the Defense Threat Reduction Agency. Similar programs to create smaller, so-called organs-on-chips are underway at the Defense Advanced Research Projects Agency and the National Institutes of Health.
“The original impetus for this research comes from the problems we are having in developing new drugs,” explained Dr. Wikswo. “A number of promising new drugs that looked good in conventional cell culture and animal trials have failed when they were tested in humans, many due to toxic effects. That represents more than $1 billion in effort down the drain. Our current process of testing first in cell lines on plastic and then in mice, rats, and other animals simply isn't working.”
Researchers and clinicians around the world have been working to develop more relevant and advanced laboratory tests for drug efficacy and toxicity: small bioreactors that can form human organ structures and are equipped with sensors to monitor organ health.
Ultimately, the goal is to connect the individual organ modules chemically in a fashion that mimics the way the organs are connected in the body, via a blood surrogate. The ATHENA researchers hope that this homo minutus, with its ability to simulate the spatial and functional complexity of human organs, will prove to be a more accurate way of screening new drugs for potency and potential side-effects than current methods.