The first chemical circuit developed

Klas Tybrandt, doctoral student in Organic Electronics at Linköping University, Sweden, has developed an integrated chemical chip. The results have just been published in the prestigious journal Nature Communications. The Organic Electronics research group at Linköping University previously developed ion transistors for transport of both positive and negative ions, as well as biomolecules. Tybrandt has now succeeded in combining both transistor types into complementary circuits, in a similar way to traditional silicon-based electronics.

An advantage of chemical circuits is that the charge carrier consists of chemical substances with various functions. This means that we now have new opportunities to control and regulate the signal paths of cells in the human body. “We can, for example, send out signals to muscle synapses where the signalling system may not work for some reason. We know our chip works with common signalling substances, for example acetylcholine,” says Magnus Berggren, Professor of Organic Electronics and leader of the research group.

The development of ion transistors, which can control and transport ions and charged biomolecules, was begun three years ago by Tybrandt and Berggren, respectively a doctoral student and professor in Organic Electronics at the Department of Science and Technology at Linköping University. The transistors were then used by researchers at Karolinska Institutet to control the delivery of the signalling substance acetylcholine to individual cells. The results were published in the well-known interdisciplinary journal PNAS. In conjunction with Robert Forchheimer, Professor of Information Coding at LiU, Tybrandt has now taken the next step by developing chemical chips that also contain logic gates, such as NAND gates that allow for the construction of all logical functions. His breakthrough creates the basis for an entirely new circuit technology based on ions and molecules instead of electrons and holes.

Eye implants help restore sight

Technology has always strived to match the incredible sophistication of the human body. Now electronics and hi-tech materials are replacing whole limbs and organs in a merger of machine and man. Later this year a team of researchers will try out the first bionic eye implant in the UK hoping to help a blind patient see with their damaged eye, unlike alternative approaches that use a camera fitted to a pair of glasses. The light-sensitive chip is attached under the retina at the back of the eye. It converts light into electrical impulses which are then sent to the brain. The patient is then able to interpret the light falling onto the tiny 1,500 pixel implant as recognisable images. The implant costs about £65,000 ($100,000; 80,000 euros) excluding surgery and maintenance costs. Clinical trials in Germany have restored sight to some patients who were completely blind due to retinal disease. They were able to read and see basic shapes after the chip was fitted. Prof Robert MacLaren, will lead the trial at Oxford Eye Hospital, along with Tim Jackson at King’s College Hospital. In the video Prof MacLaren demonstrates the Retina Implant It is one of the extraordinary medical breakthroughs in the field, which are extending life by years and providing near-natural movement for those who have lost limbs. Over the coming weeks, BBC News will explore the field of bionics in a series of features. We start with a selection of the latest scientific developments. The Bionic Bodies series on the BBC News website will be looking at how bionics can transform people’s lives. We will meet a woman deciding whether to have her hand cut off for a bionic replacement and analyse the potential to take the technology even further, enhancing the body to superhuman levels. The series continues on Wednesday with a look at some of the earliest prosthetics from ancient Egypt. http://www.bbc.co.uk/news/health-17235058

Specially prepared muscle cells into a 3-D printer

In a small clean room tucked into the back of San Diego–based  startup Organovo, Chirag Khatiwala is building a thin layer of human skeletal muscle. He inserts a cartridge of specially prepared muscle  cells into a 3-D printer, which then deposits them in uniform, closely  spaced lines in a petri dish. This arrangement allows the cells to grow  and interact until they form working muscle tissue that is nearly  indistinguishable from something removed from a human subject.

The technology could fill a critical need. Many potential drugs that  seem promising when tested in cell cultures or animals fail in clinical  trials because cultures and animals are very different from human  tissue. Because Organovo’s product is so similar to human tissue, it  could help researchers identify drugs that will fail long before they  reach clinical trials, potentially saving drug companies billions of  dollars. So far, Organovo has built tissue of several types, including  cardiac muscle, lung, and blood vessels.

Unlike some experimental approaches that have used ink-jet printers  to deposit cells, Organovo’s technology enables cells to interact with  each other much the way they do in the body. They are packed tightly  together and incubated, prompting them to adhere to each other and trade  chemical signals. When they’re printed, the cells are kept bunched  together in a paste that helps them grow, migrate, and align themselves  properly. ­Muscle cells, for example, orient themselves in the same  direction to create tissue that can contract.

So far, Organovo has made only small pieces of tissue, but its  ultimate goal is to use its 3-D printer to make complete organs for  transplants. Because the organs would be printed from a patient’s own  cells, there would be less danger of rejection.

Organovo plans to fund its organ-­printing research with revenue from  printing tissues to aid in drug development. The company is undertaking  experiments to prove that its technology can help researchers detect  drug toxicity earlier than is possible with other tests, and it is  setting up partnerships with major companies, starting with the drug  giant Pfizer. http://www.technologyreview.com/biomedicine/39687/page1/#photo

DNA nanorobots deliver ‘suicide’ messages to cancer cells

Researchers at Harvard University’s Wyss Institute for Biologically Inspired Engineering have developed a nanorobotic device made from DNA that could potentially seek out specific cell targets within a complex mixture of cell types and deliver important molecular instructions, such as telling cancer cells to self-destruct. Inspired by the mechanics of the body’s own immune system, the technology might one day be used to program immune responses to treat various diseases. Using the DNA origami method  (complex 3-D shapes and objects are constructed by folding strands of DNA), the researchers created a nanosize robot in the form of an open barrel whose two halves are connected by a hinge.

Recognition molecules – The nanorobot’s DNA barrel acts as a container that can hold various types of contents, including specific molecules with encoded instructions that can interact with specific signaling receptors on cell surfaces, including disease markers. The barrel is normally held shut by special DNA latches. But when the latches find their targets, they reconfigure, causing the two halves of the barrel to swing open and expose its contents, or payload.

Programming cancer-cell suicide – The researchers used this system to deliver instructions, encoded in antibody fragments, to two different types of cancer cells — leukemia and lymphoma. In each case, the message to the cell was: activate your apoptosis or “suicide switch” — which allows aging or abnormal cells to be eliminated. This programmable nanotherapeutic approach was modeled on the body’s own immune system, in which white blood cells patrol the bloodstream for any signs of trouble. These infection fighters are able to home in on specific cells in distress, bind to them, and transmit comprehensible signals to direct them to self-destruct. This programmable power means the system has the potential to one day be used to treat a variety of diseases. http://www.sciencemag.org/content/335/6070/831