If we could artificially grow a real working organ with the complexity of a lung or a heart outside the lab and customize it to match someone’s own tissue, we could completely reverse the transplant crisis. organ that kills 17 people in the United States every day. .
A breakthrough that has brought us closer to this reality is the creation of miniature organs, called organoids, which resemble the brain, kidneys, lungs, stomach, liver and complex tissues. These organoids are not only a futuristic and hopeful solution to organ shortages or transplant rejection, scientists are using them to understand how humans and diseases develop.
But a challenge for this company is to see what exactly is going on inside the organoid – how its cells behave and interact with each other, how they respond to new stimuli like drugs or hormones from growth – without being invasive or damaging.
In a study published this week in the journal Biosensors and bioelectrics, researchers from Washington University in St. Louis and Michigan State University in East Lansing have developed living heart organoids that can beat and contract like normal human hearts can. They tracked the growth of a heart organoid using a new imaging device called optical coherence tomography (OCT) – which could give scientists a three-dimensional view behind the scenes of an organoid as it grows and reacts to its environment, and may help lead to new knowledge that could advance the further development of artificial organs.
“You can think of OCT as an optical analogy to ultrasound,” Chao Zhou, biomedical engineer at WUSTL and co-author of the study, told The Daily Beast. During an ultrasound, a probe sends a beam of sound waves through the body. Whatever sound waves are reflected create the image you see on the screen. Similarly with OCT, Zhou said, near-infrared light waves shine onto the growing organoid, and a nearby detector collects the reflected waves and images them.
Because near-infrared light waves are much shorter than sound waves, the technique allowed researchers to see minute details of an organoid down to thousandths of a millimeter.
Zhou and his colleagues were able to watch a heart organoid grow from a small clump of stem cells into a larger blob that formed connecting chambers and valves, and even contracted spontaneously like a real heart within days.
There are still some minor design issues to be resolved in order to make OCT a valuable tool for scientists working in the field of tissue engineering. Since the OCT device sits outside the incubator where the growing organoids are kept, the researchers had to move them between the OCT device and the incubator.
“When we imagine organoids outside the incubator, they are not in their original environment, and many functions can change when you change the environment,” Zhou said. In the future, the team hopes to create a sort of two-in-one contraption integrating OCT into an incubator. This would reduce manual labor and increase the frequency at which scientists can monitor an organoid, whether hourly or minute-by-minute over a period of days.
OCT is already being used to study cancer using tumor organoids, Zhou said. But improving the frequency of monitoring would be useful for studying the effects of a drug on an organoid, allowing scientists to see immediately in real time how cancer drug candidates or substances like alcohol affect tissue. Obtaining real-time information would even help to detect when an anomaly appears during embryonic or organic development.
And when it comes to creating organs for transplantation, Zhou and Ming hope OCT can help scientists overcome technological limitations that prevent a broader understanding of all the factors that shape function and three-dimensional structure. organs like the heart.
“For example, we don’t really understand how the human heart forms from embryo to adult,” Yixuan Ming, the study’s lead author, told The Daily Beast. He added that the heart organoid the researchers created from stem cells looked more like a fetal heart than an adult human heart.
It will be a long time before we see organoids reach a potential that can treat disease, persistent organ shortages, or help transplant patients grow their own organs. But OCT could improve our understanding of the human body enough that the time it takes to get there dramatically decreases.