Photo Credit: iStock
They’re about the size of a computer memory stick, yet they could represent the greatest potential for non-animal-based scientific advancement in history. They’re called “organs-on-chips”—and they just might change the way researchers model diseases, develop drugs and approach personalized medicine. And in the process, they’ll save the lives of countless animals.
Chances are, you’ve heard about organs-on-chips—at least in passing. These tiny devices have been getting a lot of attention lately, both in the media and within the scientific community. But what are they, exactly?
Organs-on-chips are specially-constructed systems that are designed to replicate the structure and function of human organs. Each “organ” contains transparent channels lined with living human cells. Multiple cell types can be incorporated into these devices to better mimic the complex microenvironments of human organs. The cells can be grown in such a way that enables them to change shape and respond to physical cues in ways that are not possible with traditional cell-based models.
An organ-on-a-chip developed at the Massachusetts Institute of Technology. Imperial College London researchers recently published a study in which they found that a liver chip developed by MIT and CN Bio, a British firm, responded to a hepatitis B viral infection just like a real human liver would. (image credit: Felice Frankel/MIT)
Variations of these chips have already been developed and continue to be optimized. Among them are models of the human lung, liver, kidney, gut, bone, brain and heart, among others.
The first organ-on-a-chip to be developed was the lung-on-a-chip, which has lung and blood vessel cells grown on opposite sides of a flexible, porous platform that can expand and contract like a breathing lung. This model has been used to study chronic obstructive pulmonary disease, asthma, cancer and even the effects of smoking on bronchial cells.
There’s a lot of excitement about organs-on-chips because they offer the potential of making drug development and toxicology testing faster and cheaper, in addition to being more accurate and more relevant to the human body.
And importantly, many believe that these devices have the potential to drastically reduce—even replace—the need for animal testing in many areas of research.
Researchers who developed the first organs-on-chips did so, in large part, to overcome limitations of the current drug development pipeline. Drugs that make it to human clinical trials are often unsuccessful because the animal models they are tested in do not accurately predict how the drugs will work in people. An estimated 30 percent of drugs that show promise in preclinical animal models fail in human clinical trials because they are toxic to humans. An additional 60 percent of drugs fail because of lack of efficacy. This wastes time, resources and countless animal lives.
The fact that 90 percent or more of these drugs that worked in animals subsequently failed in humans meant there was an urgent need to develop a human-relevant alternative to facilitate drug development and advance personalized medicine. Organ-on-a-chip technology is one response to this need, and it has been developing rapidly over the past several years.
Here are some of the exciting advancements that have been made recently.
Regulatory agencies, including the Food and Drug Administration (FDA), are very interested in the organ-on-a-chip devices. Last year, the FDA announced a multi-year research and development agreement with Emulate, a company that makes organs-on-chips, to use the devices in food safety testing. The FDA will begin conducting tests with liver-on-a-chip devices to determine whether they can serve as effective models for studying the effects of potential hazards in food and dietary supplements.
The FDA is also interested in how individual organs process cosmetics and dietary supplements and may carry out testing of additional organ chips, including kidney, lung and intestine models. This marks the first time that a U.S. regulatory agency has actively pursued the use of organs-on-chips as animal testing alternatives.
Organs-on-chips are also revolutionizing the field of personalized medicine, which uses a patient’s unique genetic background and medical history to develop therapies and treatments that directly address the unique biology of each individual.
Earlier this year, Emulate and Cedars-Sinai Medical Center in Los Angeles announced that they are collaborating to begin a revolutionary Patient-on-a-Chip program. In this program, cells from patients will be incorporated into organ-on-a-chip devices to generate models that allow for the most effective, patient-specific treatments to be identified. This approach has tremendous potential for improving patient health.
Even Big Pharma sees the potential for organs-on-chips, with multiple pharmaceutical companies now incorporating these cutting-edge devices into their research and development pipelines.
Recently, Emulate also announced partnerships with Takeda Pharmaceuticalbased in Japan and Roche, a Swiss-based company. The companies plan to use organ chips to generate human-relevant data that they believe will better predict the safety and efficacy of drug candidates.
But the potential of organs-on-chips doesn’t end with individual organs. Because they are modular devices, it’s possible to link individual organs-on-chips together to create a human-relevant, multi-organ model system. In fact, the goal of the Human-on-a-Chip project, which represents a collaboration between the Food and Drug Administration (FDA), the Defense Advanced Research Projects Agency (DARPA) and the National Institutes of Health, is to generate a miniature 3-D model which includes 10 different human mini-organs linked together to form a physiological system, which would be more likely to mimic the activities and biological processes of the human body.
A team led by Dr. Linda Griffith, a biological engineering professor at Massachusetts Institute of Technology, has recently reported that they successfully reached this milestone, after linking together 10 organ-on-a-chip systems for an entire month. Such a human-relevant model would be invaluable for drug testing, as researchers could screen for toxicity of drugs in various organs and could detect side effects of drugs. These innovative models are proving to be not only better science, but more humane, sparing the lives of so many research animals.
Because of the value organs-on-chips have in helping to reduce, and potentially replace animal use, the National Anti-Vivisection Society (NAVS)has prioritized support for the development of these models as part of its overarching mission to end the exploitation of animals used in science.
Through its affiliate, the International Foundation for Ethical Research, NAVS has, for more than 30 years, funded early career researchers with an interest in developing alternatives to animal experiments. And in recent years, NAVS has provided critical funding for projects investigating the use of organs-on-chips to study cancer cell growth and invasion, as well for the development of a gut-on-a-chip microdevice to study human intestinal inflammation—studies that are commonly performed in animal models.
Of course, only time will tell if reality will live up to all the hype. However, there’s a great deal of optimism among scientists and animal advocates that organs-on-chips will function as intended: That they will produce data that is reproducible, accurate and reliable—and that they will ultimately replace the use of animals in many areas of scientific research.
In honor of World Day for Animals in Laboratories on April 24, NAVS has released a new video, “3 Reasons to End Animal Experimentation Now.” Help spread the word about the cruelty and waste of vivisection—and about the cutting-edge alternatives that could one day make the practice a thing of the past—by watching and sharing this video: