In a handful of labs around the U.S., researchers are creating human tissue from stem cells and manipulating them to replicate the functions of human organs, all on platforms about the size of a thumb drive. This research platform is known as a "human-on-a-chip," and it has the potential to change the nature of medical treatment.
Dr. Harry Salem has been involved in his fair share of exciting scientific breakthroughs, including the creation of the breathalyzer, the infant incubator, and Nyquil.
Now, as the chief scientist for life sciences at the Edgewood Chemical Biological Center (ECBC), he’s testing the impact of chemical weapons on humans using organs mounted on microchips.
And, despite all his experience, the idea of growing organs on chips still smacks of something from a sci-fi movie, Salem says.
“A lot of these advances we used to read about in comic books but this we never read about," Salem said. "When I went to school I was taught that nerve cells don’t regenerate, now we’re doing that up in our own labs here. And they’re making organs out of stem cells, it’s fantastic,” he says.
Of course, the chips don’t literally contain miniaturized human organs. They simply hold tissue swatches that mimic a fully functioning human heart, or liver, or lung.
These tissue cultures can be grown directly on the micro-chips, but Salem and his team use 3-D printing technology to construct the organs instead.
“The advantage of the three-dimensional printing is that every time you print it you get the same copy,” Salem says.
Salem's work at the ECBC has immediate defense applications, geared mostly toward defending soldiers in the field from chemical attacks and identifying treatment options that work against chemical agents.
ECBC is one the only facility granted permission by the Organization for Prohibition of Chemical Weapons (OPCW) to create chemical warfare agents for defensive testing purposes. And, Salem says, there are very strict security and safety protocols, with only small amounts of the chemicals allowed to be created.
The ECBC is a military organization, but the so-called human-on-a-chip has implications for the broader community too, he says.
“There’s a lot of work that will be going on in this area not only to protect the soldier but to protect civilians, and not only from chemical warfare agents, but from pollutants and diseases,” Salem said.
He also says the technology is faster, more accurate and more cost effective than animal testing.
“I’ve often used the expression that humans are not 70 kilo rats," Salem said. "When we do the animal studies we have to extrapolate the effects on humans. We may not totally replace animal testing but we could select the more appropriate animal to use. We can get a pretty good idea from doing these tests in the human tissue and then extrapolate them to humans. And the reason we may eventually have to still use some type of animal test is because we’re not going to put all of the organs on a chip, we’re going to put a lot of the major ones, but then eventually you have to put it into a living organism that has everything intact.”
But nothing, Salem says, demonstrates the way that human tissue reacts to drugs and chemicals, like human tissue.
Kristin Fabre, tissue chip program manager of the Center for Advancing Translational Sciences (NCATS) at the NIH, says microchip organs will help develop safer drugs with fewer side effects.
“This technology would be able to take tissue from an individual and basically reprogram that so it’s representing all of the major organ systems, so you could essentially have a mini personalized human-on-a-chip so that you can really get an idea of what a response would be for an individual with a toxin or a drug, or whatever you’d like to test.”
Fabre says it may also be possible to create organs that express gene mutations linked to certain diseases, like cystic fibrosis, and help find a cure or effective drug therapy.
Dan Tagle is a project leader for the organ-on-a-chip research at NCATS. He says the technology is a game changer, allowing researchers to finally address some of the biggest issues in drug development.
“These are catalysts that will propel the field forward. In drug development there’s a lot of failures and it costs billions of dollars and upwards of 10-15 years to develop a single drug," Tagle says. "We are looking essentially at the biggest problem in drug development, which is failure in toxicity and lack of predictability of efficacy. And if we address these issues with organs on chips I think we’re going to be making a lot of headway in drug development.”
This technology is still in its early stages, with a handful of labs around the country working to perfect it for wider use.