Tuesday, March 19, 2013

Towards a Human Body on a chip - Part II

Is the revolution among us?

This is part II of the series about how we can accelerate the current drug development strategy by building a human body on a chip. The current drug development model is mainly based on animal testing and intensive clinical studies afterwards. Testing new drugs on animals is not only an ethical issue, but also faces crucial problems, as animals are similar to humans but do not react quite the same on new drugs than we do. Therefore, many scientists focus on designing a human body on a chip which can simulate parts of the body without the need of animal testing. By combining microfluidic chips (see my intro to microfluidics) that features the function for parts of our body, like the lung, the gastrointestinal tract or the heart, new drugs can be tested on human like models. In my last entry, the lung on a chip was described, check out the post

How far along are we with organ on a chip device?

Some of you might think that it is still a long way to go until these chips are being used for real applications. You're wrong! This revolution is already among us. In January, researchers from the Institute of Bioengineering and Nanotechnology (IBN) in Singapore have announced that they are partnering with Johnson and Hoffman La-Roche, two big pharmaceutical companies to produce and test the first commercially available liver on a chip. The liver is an important organ for the dug development, as this is the stage where all drugs are being detoxified. Harmfull substances will be reduced, however if a drug is toxic to the body and can't be detoxified by the liver, the human is in danger. Therefore, it is crucial to test new drugs on the liver to see the effect of it's toxicity.

What are the main problems?

One of the main problem in designing organ on a chip devices, is to replicate the important functions of the organ in very great detail. Especially the cells are of importance, as these interact with the drug and determine if the drug is good or bad for your body. The problem with cell cultures in a lab is that they are usually grown in a petri dish, this is a round plastic dish with a gel (called agra) which includes all the nutrients necessary for the cells to survice and grow happily. However, these cells are grown on a flat substrate, that means they can not grow as a cell network (3D) in all directions possible and therefore might not behave like they would in an organ. The researchers from IBN solve this issue by using a foam like structure, called hydroxylpropyl cellulose, which is a FDA approved materials and the building block of cotton and paper. Liver cells can naturally grow within the 3D structure of the material and therefore act more like they would in a real liver.

Sony invests in organ on a chip development

One more thing on the side note to convince you further that these organ on a chip are a promising tool for future drug testing. Yesterday, Sony announced that they are partnering with the Wyss Institute at Harvard University to develop new organ on a chips. The lung on a chip, described in my last post, was developed by researchers from the Wyss Institute. 18 months ago, Sony started to invest in life-science companies, especially those working in microfluidics and life-science technology, e.g. Micronics. The development towards the human body on a chip is definitely a very fascinating and exciting route to follow. 

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