A team of scientists at the Wake Forest Institute for Regenerative Medicine (WFIRM) in North Carolina has reported the development of “the world’s most sophisticated laboratory model of the human body.” Developed using 3D bioprinting and other biofabrication techniques, the model is made up of a system of miniaturized 3D organs and can be used for drug testing applications.
The WFIRM team says the 3D lab model can help pharmaceutical companies to speed up drug development and lower the cost of clinical trials by determining early on whether a particular drug is harmful to human organs. The sophisticated model could also, incidentally, reduce reliance on animal testing.
The miniaturized human body model is composted of many types of human cells types, each of which represents an organ in the human body and has been bioprinted into a tissue-like structure. The miniature organs reportedly measure about one-millionth the size of an adult human organ.
Despite its scale, the novel laboratory model can be used to test drugs and predict their outcomes on full-sized human tissues and organs. Each of the miniature organs in the human body model is a complex system, consisting of blood vessels, immune system cells and in some cases fibroblasts. Impressively, the tiny 3D organs perform the same functions as real human organs: the heart beats about 60 times a minute, the lungs breath air, and the liver breaks down toxic compounds.
“The most important capability of the human organ tissue system is the ability to determine whether or not a drug is toxic to humans very early in development, and its potential use in personalized medicine,” explained Anthony Atala, MD, scientist at WFIRM and the study’s senior author. “Weeding out problematic drugs early in the development or therapy process can literally save billions of dollars and potentially save lives.”
The 3D organ model, funded by the Defense Threat Reduction Agency (DTRA), has reportedly already been put to use. WFIRM scientists say the system was able to measure toxicity in several approved drugs, resulting in them being removed from the market because they were found to be potentially harmful. The toxicity detected by the 3D organ model was not found using the 2D cell culture systems and animal testing methods conventionally used. Adverse effects of the drugs were also not detected in three levels of human clinical trials, but the tiny tissue model was able to demonstrate the damage caused by the drug on human organs.
“We knew very early on that we needed to include all of the major cell types that were present in the original organ,” said co-author Aleks Skardal, PhD, formerly of WFIRM and now at Ohio State University. “In order to model the body’s different responses to toxic compounds, we needed to include all of the cell types that produce these responses.”
To keep the miniature organs healthy, the tissue model has a blood circulatory system through which a nutrient- and oxygen-rich substance is circulated throughout the organs. To match the scale of the organs, the blood network was produced using microfluidic fabrication. This approach also enabled the team to ensure that drugs and toxic molecules would be carried throughout the organs, recirculating samples over and over through each organ—the same way the heart would recirculate molecules through the blood.
“Creating microscopic human organs for drug testing was a logical extension of the work we have accomplished in building human-scale organs,” added co-author Thomas Shupe, PhD, of WFIRM. “Many of the same technologies we have developed at the human-scale level, like including a very natural environment for the cells to live in, also produced excellent results when brought down to the microscopic level.”
Last year, WFIRM scientists made headlines for the development of a 3D bioprinted multi-material tracheal tissue combining smooth muscle and cartilage cells.