Scientists have now created working models for a whole range of human organs. Including the liver, the lung, and even the female reproductive system. The devices may bear closer resemblance to computer components than human body parts. Organs on chips are new tools for human biology research
Researchers use these devices to model disease and facilitate drug development. Scientists have developed about 15 different human organs on chips. Donald Ingber, the founding director of the Wyss Institute for Biologically Inspired Engineering at Harvard University he said I think for most people, the goal is to replace animal testing and to carry out personalized medicine in a more effective way.
Human Lungs airway chip
The first of these was the lung on a chip. A clear thumb drive size device with two channels an air filled upper channel lined with human alveolar epithelial cells. A lower channel lined with blood vessel cells and a white blood cell containing solution flowing through. To more closely model human biology, the researchers also mimicked breathing motion by applying a vacuum to deform the hollow tubes lining the main channels.
He showed the work based on that mechanical forces are as important as chemicals and genes for tissue development, maintenance, and function. “This one lung alveolus chip provided proof of principle for modeling normal organ level physiology and disease, discovering new insights into the importance of physical forces, finding new therapeutic targets and even a new drug”, Ingber says.
The latest inventions is the airway on a chip. It is similar to the initial lung chip, except that instead of alveolar cells. The device is lined with human bronchial epithelial cells. The team has used this chip to model chronic obstructive pulmonary disease and asthma. They have even used this device to study the effects of smoking on the bronchial epithelium by hooking it up to a machine that burns cigarettes and inhales and exhales smoke to mimic a human smoker.
Human neurovascular unit
A group from Vanderbilt University, has created a chip to study the brain and the blood brain barrier led by John Wikswo, a biomedical engineer. “We chose to focus on the human neurovascular unit (NVU) because of the importance of the interactions between cortical neurons and the blood brain barrier (BBB) that protects them, hence the term neurovascular unit,” Wikswo said.
The NVU chip consists of a tiny cavity divided by a porous membrane separating one chamber, which represents the brain, from another chamber, which represents the surrounding vasculature. It contains cortical neurons, microvascular endothelial cells, astrocytes, and pericytes from humans. According to Wikswo, this structure “allows us to study the metabolomic response of the neurons and other cells to drugs and inflammatory signals that are delivered across the BBB.”
The team has used this NVU chip in a variety of applications. Such as investigating disease states and to study the effects of inflammation. Currently, they are also initiating a program to use this technology to test drugs for the pharmaceutical industry.
Megan McCain, a professor of biomedical engineering at the University of Southern California. This professor works with hearts on chips small eraser size devices that house live beating heart cells. To create these devices, researchers first take skin cells from patients and reprogram them into stem cells. That later develop into cardiac myocytes. They then place these cells on chips containing bio engineered surfaces. To recreate the heart’s natural environment. “The key metric that we’re interested in is the generation of force,” McCain says.
Eye on chip
Dan Huh, a bioengineering professor at the University of Pennsylvania who was a postdoc in Ingber’s lab, and colleagues have created an eye on a chip with an eyelid that blinks.
This chip, which is roughly the size and shape of a contact lens, approximates the ocular surface of the eye. In addition, it contains human cells from the cornea and conjunctiva (the mucosal layer that covers the eye). The team also engineered an eyelid, which attaches to the surface and allows the eye to blink, keeping the surface of the chip lubricated.According to Huh, his lab also plans to use this chip to model other eye conditions. For drug testing and development and to test and optimize contact lenses.
The team is also currently developing a retina on a chip. His group is also working on chips for a variety of other organs, including the lungs and placenta.
Furthermore, many groups aim to link different organ chips together to recreate organ systems or even the entire human body. Teresa Woodruff, a professor of obstetrics and gynecology at Northwestern University. Meanwhile, she and her colleagues have linked five miniature organs together in a hand size chip to model the female reproductive tract.
Menstrual cycle System
The chip, dubbed EVATAR, is a series of tubes and pumps. That carry a blue, blood like fluid through cells containing five mini organs a fallopian tube, a uterus, a vagina, an ovary, and a liver. The system allows us to do is move media in a way that brings in fresh nutrients and eliminates waste,” Woodruff says. That’s what happens in the body. By adding hormones to the circulating liquid, the team was able to mimic the 28 day menstrual cycle.
The researchers hope to use EVATAR to elucidate reproductive physiology and disease, as well as in drug testing and development. They are also working on a male version of the chip, ADATAR.
Multiple organs on single chip
Linda Griffith, a biological engineering professor at MIT and colleagues are one of two groups working on projects funded by the US government’s Defense Advanced Research Projects Agency (DARPA). Moreover, to a create “bodies on chips,” which aim to connect ten different mini organ systems in an integrated circuit. The other group is at the Wyss Institute.
Meanwhile, according to Griffith, her team recently “completed our big DARPA milestone, which is connecting 10 organ micro physiological systems for a month.”
Moreover, connecting multiple organ chips allows researchers to interrogate organ interactions. In one of their latest experiments, Griffith and her team investigated the effects of inflammation in a system. Where human intestine chips and liver chips were linked. This study revealed, among other things, how cross talk between the two organs influence gene expression and tissue specific functions.
Startup Company Emulate was formed to commercialize organ on chip technology developed at the Wyss Institute. However, including Lung Chips, Liver Chips, and Intestine Chips. While these chips possess different cell types and functions, their standardized design makes them look identical from the outside.
However, the company recently announced its plans to send its Brain Chips to the International Space Station. They used to study among other things. The blood brain barrier and how stressors and inflammation affect brain function.