Which organ on a chip devices are out there?
The most-advanced organ on a chip device is currently the lung, developed by scientists at the Wyss Institute. Another device created by the same scientists is the gut on a chip (shown below). This chip is made of PDMS (a flexible polymer commonly used in microfluidics) and features microfluidic channels. In the image below you see two different colored fluids running inside the channel and exiting on the bottom. The structure of this chip is very similar to the lung on a chip developed by the same group. It has two channels (red and blue), one is running on top of the other one. In between there is a horizontally aligned porous membrane lined with real human intestinal epithelial cells. On the side of the colored channels are two chambers which can be pressurized in a cyclical motion to mimic the digestion happening in our body. These two are the most advanced organ on a chip devices out there. Scientists are also working on creating artificial muscles to mimic the movement in the heart, as well as on organs like the kidney, liver and bones.
|Gut on a chip device|
Image courtesy: Wyss Institute
In July 2013, DARPA (Defense Advanced Research Projects Agency, USA) announced a $37 million grant for the Wyss Institute at Harward for the development of an array of organ on a chip devices. The Wyss Institute has already developed a lung, as well as the gut on a chip device above. Further projects will include the heart, liver and kidney. Furthermore, they are developing chips that will mimic the human skin and muscles. The NIH (National Institute of Health, USA) also funded several researchers all over the country to develop organ on a chip devices. Their total funding amount was $13 million. The European Union is also funding a Switzerland based company, called InSphero AG with €1.4million for 3 years (starting June 2012). InSphero is focusing to solve the 3D structure implementation of the cell cultures, one of the main problems of current devices (see part II).
What is left to do?
To create a human body on a chip, several organs have to be fabricated, including the lung, heart, bones, kidney, liver, gut (see below). Other devices of interest are the skin, arteries and muscles. Ultimately, all of these single device will be connected via tubes to each other to form the human body on a chip.
|Concept for the human body on a chip.|
Image from: D.E.Ingber, Trends in Cell Biology (2011) 21, 12, p. 745-754